DE102004053530A1 - Classifying wheel for a device for separating dusty, fibrous or granular goods - Google Patents

Abstract

The invention relates to a Sichterrad for a device for separating dusty, fibrous or granular goods after the rate of sinking under the influence of grain shape, grain size and density, consisting of a substantially cylindrical body with a concentric core or pin for receiving a drive shaft, a plurality of the cylinder circumference distributed flow openings and a fine material outlet. DOLLAR A According to the invention, the cylindrical body consists of a monolithic block, wherein the cylinder jacket wall thickness is in the range of 0.1 to 0.4, preferably 0.125 to 0.3 times the cylinder outer diameter. Furthermore, webs remain in the cylinder jacket between the flow openings and the flow openings are designed as slots extending in the cylinder longitudinal direction and / or a multiplicity of radially oriented bores.

Description

The The invention relates to a classifying wheel for a device for separation dusty, fibrous or grainy Goods after the rate of descent under the influence of grain shape, grain size and density, consisting of a substantially cylindrical body with a concentric core or pin for receiving a drive shaft, a variety over the cylinder circumference distributed flow openings and a fine material outlet, according to the generic term of claim 1

winnowing presents itself as a process for separating dust-like, grained or fibrous goods, the separation according to the rate of descent under the influence of grain shape, Grain size and density he follows.

One quality criterion an air classifier is the separating effect, where possible all particles larger than the separating boundary are, into the coarse material and smaller particles into the fines promoted become.

For air classifier come so-called sifter wheels from e.g. Steel or ceramics are used, with the possibility also There are several classifying wheels in a device to achieve an increase in performance.

Through the use of safes of Al ₂ O ₃ or SiC in conjunction with a corresponding lining of a classifier can be achieved that iron abrasion-free powders are available. Conventionally used for classifier wheels have a substantially cylindrical shape with a bottom and a cover plate, wherein usually in or on the bottom plate a receptacle for a motor drive, in particular for a drive shaft is provided.

Between the over Spacers spaced apart from each other is a plate Variety of conveyor blades, which for the necessary flow of goods in conjunction with the aforementioned drive to care. The shovels associated with the abandoned good have to extremely durable especially at high speeds and be abrasion resistant to a technologically meaningful life of the respective Classifier wheel to reach.

With respect to the use of a classifier wheel within a flow chamber classifier head, refer to the multifunctional apparatus for grinding, sifting, mixing and / or deagglomeration according to DE 100 45 160 A1 made aware. Also in the local device is a Sichterrad application, which has a plurality of radially oriented blades between two opposite circular surfaces. The known classifier consists of a classifier housing with a spiral outlet for fines and has a closable by a door opening; wherein the Sichterrad is adjustably mounted rotatably mounted on the door and the door is externally connected to an electric motor drive. In this way, it is ensured that only the classifier wheel itself comes into contact with the material to be inspected and damage to the axis or the receptacle for the classifier wheel can be largely excluded.

It However, it has been found that known sizing wheels in terms the selectivity, the yield of fines and the life still not all requirements suffice for various applications. In particular occurs at usual Sifter wheels in particular at the fines exit a very high, hardly avoidable wear on, with the consequence that one more or less frequent Changing the Sichterrads and thus a production interruption becomes necessary.

Out The above, it is therefore an object of the invention, an evolved Classifier wheel for one Device for separating dust-like, fibrous or grainy Goods after the rate of sinking under the influence of grain shape, grain size and density indicating, this classifier wheel compared to the prior art longer Service life by a more even Wear, to ensure finer separation limits and even finer finished goods, in particular the latter quality criterion by applying higher To secure speeds.

The solution The object of the invention is achieved with a Sichterrad according to the feature combination according to claim 1, wherein the dependent claims at least expedient embodiments and Developments include.

at the proposed Sichterrad is of a known, essentially cylindrical body assumed that the cylindrical body has a concentric core or pin for receiving a drive shaft, preferably for a having a motor drive and a plurality distributed over the circumference of the cylinder flow openings and has a fines exit.

According to the invention, the cylindrical body consists of a monolithic block, wherein the cylinder jacket thickness is chosen substantially larger compared to the prior art. The cylinders shell thickness is in the range of 0.1 to 0.4, preferably 0.125 to 0.3 times the cylinder outer diameter.

Between the, e.g. by milling introduced flow openings remain significant webs in the cylinder jacket, so that for a sufficient Strength against Wear worry will be carried. The flow openings are according to the invention as in Cylinder longitudinal axis direction extending slots and / or a plurality of radially oriented Holes formed.

at a preferred embodiment of the invention, the width of the Slots smaller than the width of the remaining webs predetermined.

The Slits extend, optionally interrupted by a Support ring, over the Length of the almost entire cylinder.

in the Case of the formation of the flow openings as bores are in one embodiment, the bore longitudinal axes each to the longitudinal axis directed towards the cylinder.

alternative it is possible, the bore longitudinal axes at an angle at an angle to arrange running, with the imaginary extended bore longitudinal axes outside the cylinder longitudinal axis to cut.

The oblique arrangement or oblique orientation the holes runs preferably in the direction of rotation of the classifier wheel.

Based on a Cartesian coordinate system originating on the cylinder longitudinal axis is the skew angle the holes in the range between 30 ° and 60 °, preferably between 40 ° and 50 °.

The respective holes in the circumferential direction of adjacent rows of holes are arranged staggering staggered.

At the drive end, the cylindrical body has a chamfer, which is usually inclined or can be executed as a circular arc section.

Of the cylindrical body consists in a preferred embodiment of plastic, in particular a hard polymer.

Farther comprises the cylindrical body a metal core insert which in turn receives a drive shaft serves.

Of course you can the Sichterrad also made of a metallic or ceramic material without departing from the spirit of the invention.

With Use of the classifier wheel according to the invention it has been shown that by the multitude of flow openings, especially holes, the flowing air or the product-air mixture very much evenly over the full area of the Rades distributed. This results in a very uniform and low overall load on the wheel, i. the wheel surface, where in the quintessence, longer ones Stand times arise.

By the arrangement of holes in the monolithic body in an area ratio bore to remaining ridges of substantially about 1: 1 arise higher Strengths of the impeller, whereby higher peripheral speeds of ≥ 60 m / sec possible are, i. it can even finer finished goods be achieved when using the Sichterrads in an air classifier.

All in all leads the Use of the presented Sichterrads for a better selectivity, a higher Fines yield, which in turn is available low-fines coarse material.

The Invention will be described below with reference to an embodiment and below With the help of figures closer explained become.

in this connection demonstrate:

1 an illustration of a Sichterrads with longitudinal slots in the partial cross-section and partial longitudinal section;

2 a representation similar to the 1 but with a classifier wheel with inner reinforcing ring;

3 an illustration of a hole-Sichterrads in partial cross-section and partial longitudinal section;

4 a three-dimensional view of a virtually realized hole Sichterrads and

5 a detailed representation of the hole Sichterrads after 4 with recognizable obliquely oriented holes, circumferentially distributed over the cylinder jacket.

The classifier wheels shown in the embodiments have a substantially cylindrical shape with a bottom portion which is designed flange-like and with respect to the cylinder longitudinal axis 2 a steel core insert 3 to the Auf having a drive shaft, not shown.

At the opposite end of the bottom of the cylindrical Sichterrads this has an opening portion 4 on, which serves the fines exit.

From the representations especially after the 1 to 4 It is clear that deviating from the known prior art, the thickness or thickness of the cylinder jacket is very large and, for example, in the range to 0.1 to 0.4, preferably 0.125 to 0.3 times the cylinder outer diameter.

In the cylinder jacket 5 are, as shown in the figures, flow openings introduced.

According to the 1 and 2 the flow openings are in the form of slots 6 realized. Between the adjacent slots remain webs 7 whose web width is greater than the slot width in the embodiment shown.

The slots are in the embodiment according to 2 through a support ring 8th interrupted, so that the necessary overall stability of Sichterrads results even with larger longitudinal dimensions.

The slots 6 preferably extend over the entire length of the cylindrical body except the bottom portion 1 ,

The preferred direction of rotation of the classifier wheel is in the respective left part of 1 to 3 symbolized by an arrow.

Like in the 1 recognizable, there is the possibility of the slots 6 also to run obliquely. This means that in contrast to the embodiment of 1 the imaginary longitudinal axes of the slots 6 not on the cylinder axis 2 meet or cut there.

With respect to an imaginary coordinate system, which has its origin on the cylinder longitudinal axis 2 has, are the slots 6 as shown by 1 oriented at an angle of, for example, 45 °.

In the embodiment according to the drawing according to 3 or the illustrations according to the 4 and 5 is assumed by a hole-Sichterrad, which also has a floor area 1 , a cylindrical longitudinal axis 2 , a steel core insert 3 and an opening section 4 having.

Also in this embodiment, the cylinder jacket 5 a relatively large thickness or wall thickness.

In the cylinder jacket 5 are in a modification to the first embodiment hole-like holes 9 brought in.

The longitudinal axes of the holes 9 can each be directed towards the longitudinal axis of the cylinder (not shown) or at a predetermined angle (see 3 , left part of the picture).

Accordingly, the bore longitudinal axes of the holes 9 arranged obliquely at an angle, wherein the imaginary extended bore longitudinal axes outside the cylinder longitudinal axis 2 to cut.

The oblique orientation of the holes 9 runs preferably in the direction of rotation of the Sichterrads (see arrow).

Based on a Cartesian coordinate system originating on the cylinder longitudinal axis 2 is the skew angle of the holes 9 in the range between 30 ° and 60 °, preferably between 40 ° and 50 °.

The respective holes 9 in the circumferential direction of adjacent rows of holes have a staggered arrangement, as shown in 3 , right part of picture becomes clear.

At the drive end, the cylindrical body according to the embodiments have a chamfer 10 on.

in the Compared to standard classifying wheels occurs in the embodiments according to the invention, in particular a lesser one for those with a large number of holes or holes and circumferentially even wear on, so that longer life result.

The classifying wheels can be made of machinable steels as well as ceramics such as Al ₂ O ₃ , zirconium oxides, SiC or the like, but also of polyurethanes or plastics.

The Geometries of the holes respectively the slots in the wheel are in the Area of invention theory freely selectable and can be accordingly the chosen one Realize material types of the wheel by machining processes.

Experiments with kaolin using the air classifier with inventive Sichterrad at the same Sichterrad speed have shown that the maximum fine fineness in an inventive ßen Lochrad D 95%, 5.7 microns. On the other hand, the fineness of a standard wheel is 8.0 μm.

Of the Misfire content in a standard wheel is in the range between 33% and 34%; in a pinwheel according to the invention, however, only in Range between 30% and 32%. Despite much finer separation results When using the theory of the invention a better proportion of defective grain.

at further attempts with sand was a significantly better selectivity and thus detected fines yield. The false grain share was here for a standard wheel in the range between 15% and 16%, the pinwheel according to the invention at about 5%.

1

floor area

2

cylinder longitudinal axis

3

Steel core insert

4

opening section

5

cylinder surface

6

slot

7

web

8th

support ring

9

drilling

10

chamfer

Claims (11)

Classifying wheel for a device for separating dusty, fibrous or granular goods at the rate of descent under the influence of grain shape, grain size and density, consisting of a substantially cylindrical body with a concentric core or pin for receiving a drive shaft, a plurality of flow openings distributed over the circumference of the cylinder and a fines exit, characterized in that the cylindrical body consists of a monolithic block, wherein the cylinder jacket wall thickness is in the range of 0.1 to 0.4, preferably 0.125 to 0.3 times the cylinder outer diameter, webs between the flow openings remain in the cylinder jacket and the flow openings are formed as extending in the cylinder longitudinal slots and / or a plurality of radially oriented holes. Classifying wheel according to claim 1, characterized in that that the Width of the slots smaller than the width of the remaining webs is. Classifier wheel according to claim 1 or 2, characterized that the Slots, possibly interrupted by a support ring on the Length of the Cylinders are arranged extending. Classifying wheel according to claim 1, characterized in that that the longitudinal axes the bores in each case to the longitudinal axis directed towards the cylinder. Classifying wheel according to claim 1, characterized in that that the bore longitudinal axes at an angle at an angle are arranged extending, with the imaginary extended bore longitudinal axes outside the cylinder longitudinal axis to cut. Classifying wheel according to claim 5, characterized in that that the oblique orientation the holes runs in the direction of rotation of the wheel. Classifying wheel according to claim 5 or 6, characterized that related on a Cartesian coordinate system originating on the cylinder longitudinal axis the skew angle in the range between 30 ° and 60 °, preferably between 40 ° and 50 °. Classifying wheel according to claim 1, 4, 5, 6 or 7, characterized characterized in that respective holes offset in the circumferential direction of adjacent rows of holes are arranged to each other. Classifier wheel according to one of the preceding claims, characterized characterized in that Drive end of the cylindrical body has a circumferential chamfer. Classifier wheel according to one of the preceding claims, characterized characterized in that cylindrical body made of a plastic, in particular hard polymer material. Classifying wheel according to Claim 10, characterized that the cylindrical body a metal core insert.