DE3102420C2 - Cutting unit for processing liquids with a high fiber content - Google Patents

Abstract

Cutting unit for processing liquids interspersed with a high fiber content, preferably with straw or the like. contaminated manure, with stationary knives that move past them, in which both the movable and the stationary knives (11a, 11b, 12) of the cutting unit have straight cutting edges (16, 17, 18) which are located on the rotor or on the housing of the cutting unit each forming generatrices of a single-shell hyperboloid, the axis of the hyperboloid corresponding to the cutter axis and the fixed cutting edge (s) being inclined in a manner opposite to the movable cutting edges.

Description

The invention relates to a cutting unit for processing liquids with a high fiber content, manure, preferably with straw or the like, according to the preamble of claim 1.

A cutting unit of this type, in which the cutting edges of the fixed knives on radii and the The cutting edges of the rotating knives on the rotor lie on parallels to radii, is from the US-PS 33 19 896 known. This ensures a pulling cut.

When keeping animals in stables in agriculture Often the excrement (excrement and urine) as well as certain amounts of litter and leftover feed are used as liquid manure or flowing manure collected in pits. These must be emptied at certain intervals. To do this, sometimes after reprocessing, suitable pumps or vacuum vessels are used. As it is during storage manure is often used for sedimentation, i.e. for depositing a sinking layer and for ascending a floating layer comes, the Saugleitjng des Clog the slurry tank or the slurry pump very easily. To avoid such blockages be Cutting units, such as the known cutting unit mentioned at the outset, is used. A similar cutting unit is used from DE-PS 10 52 734 known, although on the possibility of a pulling cut has not been accepted

Despite all the advantages of the pulling cut, the known cutting device mentioned at the beginning does not always work satisfactory. In particular, it has a high cutting force necessary. In addition, a spring preload is required in the known cutting unit, in order to achieve a contact between the cutting edges and thus a certain self-sharpening effect as well as evasion in the axial direction when stones or the like are sucked in during rough operation will. However, if the spring is clogged, this can no longer be guaranteed, so a Safe continuous operation is no longer guaranteed.

However, if there are signs of wear, the cutting units become ineffective and blockages occur on. It is very difficult to regrind the cutting edges and to replace the knives however, it is costly.

In addition to such cutting units, agitators without stationary counter knives are known (DE-PS 11 39 318). In such agitators, the formation of the cutting edges is οκinbar insignificant, they can in be arranged in a plane normal to and / or inclined to the axis of rotation. There are also arrangements with Impact mechanisms known (DE-PS 10 01 096) whose cutting edges can be arranged obliquely to the axis, which also interact with a perforated screen wall. Such arrangements can despite the high cutting force required, cannot guarantee reliable maceration.

The invention is based on the object of designing a cutting unit of the type mentioned at the outset in such a way that that despite the simple structure, a more uniform and lower cutting force is achieved; d.

The object is achieved by the characterizing features of claim 1

The invention is further developed by the features of the subclaims allow easy resharpening and / or interchangeability.

Due to the special arrangement of the cutting edges as a straight generating line of a single-shell hyperboloid compared to the known arrangement of the cutting edges in a plane perpendicular to the axis is a A more uniform and lower cutting force is achieved, with the cutting unit and also its knife in a simpler way Wise can be formed and there is also a simple assembly option. Since further pulling Cut is achieved, uniform and low cutting force and a clean cut is also guaranteed can self-sharpening of the cutting edges and with a suitable angle of the cutting edges with a plane perpendicular to the cutting axis a rejection of solids sucked in, such as stones or the like is achieved will. Furthermore, the number of rotating knives compared to the fixed knives can be freely selected are, for example, such that each rotating knife has at least two fixed cutting edges touched at the same time. Furthermore, the rotating knives can be arranged displaceably on their support ribs be and due to centrifugal force at at least two points of the (assigned) fixed

Put on knife. This results not only in the effective cut with a simple arrangement, but also a self-sharpening effect without the need for special measures such as pre-tensioning or the like would be required. It should also be noted that when moving the rotating knife opposite the fixed knives result in a mutual displacement of the cutting edges, which appears as apparent Rotation of the knife profile around the cutting edge represents a change in the clearance angle results in the pulling cut.

The invention is explained in more detail with reference to the embodiment shown in the drawing

F i g. 1 the geometric representation of a single-shell Hyperboloids and their generators,

2 shows a diagram of a cutting mechanism according to the invention.

F i g. I shows in a three-dimensional view the position of two straight lines 1 and 2, the mirror-inverted generators a single-shell hyperboloid 3 drawn in thin lines are shown. There are the hints! 4th and 5, the straight lines 1 and 2 with the plane 6, also shown in thin lines, perpendicular to the Include cutterbar axis of the same size, but inclined in the opposite direction, when remaining in place Straight line 2, the straight line 1 rotated around the axis 7 of the hyperboloids 3 so come according to the laws of Geometry all corresponding points, that is to say lying on parallel circles of the hyperboloid 3 two straight lines 1 and 2 in contact with each other.

F i g. 2 shows an example of the principle explained above implemented on a submersible pump. It is. an impeller 9 of the submersible pump with hub 10 as a rotor including the one attached to it on support ribs 15 and thus rotating knives 11a and 116 (in the present Embodiment two opposing knives are shown) from the spiral housing 13 of the Submersible pump with suction mouth arranged on the shaft side shown pulled out

The fixed knife 12 (in the exemplary embodiment a single knife is provided) is provided with a corresponding one Support body 14 mounted on the suction mouth of the spiral housing 13

Both the rotating knives 1 \ a, 11 b and the stationary knife 12 have cutting edges 16, 17 and 18, respectively, which correspond to the rectilinear generatrices of the single-shell hyperboloid, so that the material to be cut when the rotating knives 11a, Mb come into contact with the fixed knife 12 is severed at the cutting edges 16, 17 and 18 by a pulling cut.

In another embodiment of the invention, not shown, the rotating knives Ua, 116 arranged on the support ribs 15 so that they can be displaced net that they are fixed by centrifugal force on the fixed in this case provided in sufficient numbers Support knives 12 at at least two points each (close fitting). In addition to exact (pulling) Cut also achieved an improved self-sharpening effect. In addition, by evading the knife can be damaged to a certain extent when it hits stones or the like avoid.

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For this purpose 2 sheets of drawings

Claims (5)

Patent claims: 1. Cutting unit for processing liquids with a high fiber content, preferably manure covered with straw or the like, in which both the rotating knives sitting on the rotor and the stationary knives sitting on the housing Knives have straight cutting edges, the angular position of the meeting Cutting edges ensure a pulling cut, characterized,
that the cutting edges (16, 17; 18) are each rectilinear generatrix (1, 2) of a single-shell hyperboloid (3), the axis (7) of which corresponds to the cutting mechanism axis, these cutting edges (16, 17; 18) being laid tangentially to the equator of the hyperboloid (3) by one paraxial cutting plane delivered straight line pair bikiin and the cutting edge (18) of the at least one fixed knife (12) are inclined in a mirror-inverted manner in relation to the cutting edge (16, 17) of the at least one rotating knife (11 a, 11 b). 2. Cutting device according to claim 1, characterized in that the cutting edges (16,17; 18) with a Plane (6) perpendicular to the cutter axis each enclose an angle (4 or 5) of about 60 °. 3. Cutting device according to claim 1 or 2, characterized in that the number of rotating knives (Ua, Ub) differs from that of the fixed knives (12) 4. Cutting device according to one of claims 1 to 3, characterized in that ^ edes circumferential Knife touches at least two fixed knives at the same time. 5. Cutting device according to one of claims 1 to 4, characterized in that the rotating knives (11a, Ub) are arranged displaceably on support ribs (15) on the rotor (10) and, due to the centrifugal force, sit at least at two points on the stationary knife (12 ) issue. 45