EP1786573B1 - Apparatus for classifying charge material - Google Patents

Abstract

The device has a static separator (1) with an inclined aeration base (1a) through which separator gas (2) flows, where the aeration base is arranged in a vertical direction. An inlet opening (3) feeds raw material (9) to the aeration base, and an outlet opening (4) is provided for coarse particles. A downstream dynamic separator (5) has a rotor (5a) and another outlet opening for the separator gas loaded with fine particles. A ratio of breadth to height of the aeration base is 0.6.

Description

The invention relates to a static-dynamic sifter for sifting feedstock with a static sifter having an inclined to the vertical aligned, traversed by classifying gas ventilation floor and a downstream dynamic classifier.

From the DE 42 23 762 For example, there is known a sifter for sifting granular material having a rod sifter and an upstream, shaft-shaped cascade sifter. This cascade classifier has two inclined to the vertical, opposite and between them a caution zone forming Schachtbegrenzungswände, which are permeable to the Sichtluft. The shaft boundary walls are formed by inclined, louvre-like baffles, which are traversed by view air across. The cascade classifier is operated in circulatory operation with a good bed roller mill, wherein the baffles serve for deagglomerating, ie for unlocking the slugs formed in the high-bed roller mill. The feed material is fed from above the cascade classifier and falls over the staircase-like baffles down and is thereby deagglomerated and sighted. The fines, along with the classifying air, are fed to the rod cage sifter while the coarse components are led down.

The dimensioning of the feed to the separator takes place on the basis of the Gutströme to be handled and provides compact narrow mass flows compared to the classifier. The requirements for a high visual efficiency demand on the one hand the limitation of the feed quantity per classifier width and on the other hand a sufficient number of - from material flow direction - sequentially switched sight levels of the cascade. Another important factor influencing the visual efficiency is the uniformity of the width distribution of the visible material and the classifying air. With wider classifiers, this uniformity is more difficult to realize, which is why the number of vision stages increases with size. With classifiers for small feed quantities, the width / height ratio is therefore about 0.15 and increases to about 0.35 for larger quantities. These tall and narrow designs lead to high costs for the transport of materials and the buildings.

In the DE 103 50 518 Therefore, in the case of high throughput rates, a sifting device for sifting granular material is proposed which comprises a static cascade classifier with at least one viewing zone enclosed by the shaft-shaped viewing housing and an angle deviating from the vertical and a dynamic rod cage sifter. The peculiarity is that viewed in plan view, the Sichtgasseintrittsgehäuse the viewing device has a flow branching on two strands in the manner of a bifurcated tube, wherein in both bifurcated tube housing branches a cantilevered rod basket is arranged. The mirror-image oppositely arranged end-side bar basket discharge ends are brought together to the outlet of the loading gas flow laden with fines via a further housing part to a common trigger housing. According to a first variant, a static cascade classifier is arranged in each of the two branch pipe branch branches. In a second variant, a common cascade classifier is provided before the branch.

The embodiment with two separate cascade classifiers and two separate rod basket classifiers causes relatively high costs. But even the variant with a common Cascade classifier is relatively expensive, since the Cascade classifier at a high throughput due to its unfavorable width / height ratio requires a very high height.

In the EP-A-0 392 455 Furthermore, a cleaning machine is described which comprises two static visors connected in series and a separator. The DE-A-101 37 132 relates to a sifter with a chute, a first classifier, a riser, a second classifier and a separator. Both classification levels are designed as static viewing levels.

The invention has for its object to significantly reduce the height of a static-dynamic classifier and improve the visual efficiency of static-dynamic classifiers with different throughputs.

According to the invention, this object is solved by the features of claim 1.

The inventive static-dynamic sifter for sifting feed essentially consists of a static sifter which has a ventilation floor oriented obliquely to the vertical, through which viewing gas flows, an inlet opening for discharging the feed material onto the aeration floor, an outlet opening for the coarse material, a downstream dynamic one Classifier comprising at least one rotor and an outlet opening for the fine gas laden sighting gas. The aeration bottom has a ratio of width to vertical height of at least 0.45, preferably of at least 0.6.

Further embodiments of the invention are the subject of the dependent claims.

According to a preferred embodiment, a device for distributing the feed over the width of the ventilation floor is further provided. Furthermore, the static sifter expediently preceded by means for deagglomerating.

According to a preferred embodiment, the surface of the ventilation floor is flat and provided with ventilation openings, in particular ventilation slots. The ventilation floor is inclined at an angle between 20 ° and 70 °, preferably between 30 ° and 60 °, to the vertical.

According to a preferred embodiment of the invention, the ventilation floors of the devices differ in the context of a series for different throughputs only in the width and not in the vertical height of each other. This causes in addition to the already much more favorable ratio of width to vertical height and then no increase in height, if the device must be designed with a higher throughput.

Further advantages and embodiments of the invention will be explained in more detail below with reference to the description of some embodiments and the drawings.

Fig. 1

eine schematische Seitenansicht der Vorrichtung zum Sichten,

Fig. 2

eine schematische Schnittdarstellung längs der Linie III-III der Fig. 1,

Fig. 3

eine Schnittdarstellung des Details III der Fig. 1,

Fig. 4

ein Flussdiagramm einer Mahlanlage mit einer erfindungsgemäßen Vorrichtung zum Sichten,

Fig. 5

eine Seitenansicht einer Vorrichtung zum Sichten mit einer Verteileinrichtung gemäß eines ersten Ausführungsbeispiels,

Fig. 6

eine schematische Schnittdarstellung längs der Linie VI-VI der Fig. 5,

Fig. 7

eine schematische Seitenansicht einer Vorrichtung zum Sichten mit einer Einrichtung zum Verteilen gemäß eines zweiten Ausführungsbeispiels,

Fig. 8

eine schematische, teilweise geschnittene Draufsicht der Fig. 7,

Fig. 9

eine schematische Ansicht von Mitteln zum Desagglomerieren gemäß eines ersten Ausführungsbeispiels und

Fig. 10

eine schematische Ansicht von Mitteln zum Desagglomerieren gemäß eines zweiten Ausführungsbeispiels.

In the drawing show

Fig. 1

a schematic side view of the device for sifting,

Fig. 2

a schematic sectional view taken along the line III-III of Fig. 1 .

Fig. 3

a sectional view of the detail III of Fig. 1 .

Fig. 4

a flow diagram of a grinding plant with a device according to the invention for sighting,

Fig. 5

a side view of a device for sifting with a distribution device according to a first embodiment,

Fig. 6

a schematic sectional view along the line VI-VI of Fig. 5 .

Fig. 7

1 is a schematic side view of a device for sifting with a device for distributing according to a second embodiment,

Fig. 8

a schematic, partially sectioned plan view of Fig. 7 .

Fig. 9

a schematic view of means for deagglomerating according to a first embodiment and

Fig. 10

a schematic view of means for deagglomerating according to a second embodiment.

The in the FIGS. 1 to 3 shown static-dynamic classifier 100 for sifting of feed material consists essentially of a static classifier 1, which is oriented obliquely to the vertical, by the sighting gas 2 can be flowed through aeration bottom 1a, an inlet opening 3 for the task of the feed material 9 on the ventilation floor, an outlet opening 4 for the Grobgut, a downstream dynamic classifier 5, which comprises at least one rotor 5a, and at least one outlet opening 6 for the loaded with fines sighting gas 2 '.

The ventilation base 1a is inclined at an angle α between 20 ° and 70 °, preferably between 30 ° and 60 °, to the vertical. In the illustrated embodiment, the surface of the ventilation floor 1a is flat and provided with ventilation openings 1b, in particular ventilation slots (see Fig. 3 ).

The ventilation base 1a has a ratio of width b to vertical height h of at least 0.45, preferably of at least 0.6. Accordingly, the width of the ventilation floor is much larger than in known equivalent power versions and therefore contributes to reducing the height of the device for sifting crucial. (Note: At b / h = 0.6, the width is smaller than the height!).

The static sifter 1 and the dynamic sifter 5 are housed in a common housing 7, wherein the dynamic sifter in the in Fig. 1 shown side view is arranged obliquely above the ventilation floor.

The feed material 9 supplied via the inlet opening 3 slides down over the ventilation floor 1a and is traversed transversely by the viewing gas. The Fine material of the feed material is carried with the classifying gas 2 to the dynamic classifier, which comprises one or more rotors, in particular rod baskets.

The rejected in the region of the rotor medium grain fraction is passed through a disposed within the housing return 8 to the outlet opening 4 for the coarse material. The rotor is expediently mounted on both sides and can correspond in its width to the width of the ventilation floor. It would also be conceivable that the width of the rotor is larger or in particular smaller than the width of the ventilation floor is formed. For this case, a housing transition piece is provided between the static and dynamic classifier, which connects the housing sections of the housing 7 of different widths in the area of the static classifier or the dynamic classifier.

In Fig. 4 For example, the static-dynamic classifier 100 is shown for viewing with a good bed roller mill 200. The static-dynamic sifter 100 also comprises a device 101 for distributing the feed material across the width of the aeration bottom 1a and means 102 for deagglomerating the material returned from the good-bed roller mill 200 to the static-dynamic sifter.

In the Figures 5 and 6 a first embodiment of a device 101 for distributing the feed over the width of the ventilation floor is shown. This device consists in the illustrated embodiment of baffles which are arranged in the feed chute 7a of the housing 7. The baffles 101 a are designed so that they distribute the feed material 9, which is placed over conveyor 10 in a certain width, to the width b of the ventilation floor 1a.

Instead of a static device for distributing the feed but also dynamic means are conceivable. In the FIGS. 7 and 8th the device 101 is formed by a vibrating groove 101'a.

For the upstream means 102 for deagglomerating, for example, a bellows breaker 102a is used Fig. 10 in consideration, which is conveniently placed below the Goodbettwalzenmühle 200. As an alternative, for example, but also a blast wheel 102'a according to Fig. 9 conceivable.

The mass flow of the feed material on the aeration bottom 1a decreases from top to bottom, since during the residence more and more fines are discharged with the classifying air. This reduces the flow resistance of the feed material in the direction of the outlet opening 4 for the coarse material. So that the classifying air can nevertheless flow uniformly through the feed material, the aeration bottom is designed such that it produces a pressure drop of 2 mbar to 8 mbar, preferably 3 mbar to 4 mbar.

The static-dynamic classifier described above is distinguished by the fact that the aeration bottoms 1a of classifiers for a different throughput rate differ only in the width b and not in the vertical height h from each other. This means that the static-dynamic classifier only increases in width, while the overall height remains essentially the same. This, in turn, means that the visual efficiency is substantially the same for classifiers with different throughputs, since, unlike conventional devices, the dwell time, which is essentially determined by the vertical height, remains unchanged.

With increasing width, the device for distributing the feed over the width of the ventilation floor is becoming increasingly important. As part of the series consideration, the width of the dynamic rotor is preferably changed linearly with the width of the static ventilation floor. The width of the rotor may differ in principle from the width of the static stage. In particular, the requirements in the final grinding and partial finishing with partial Fertiggutausschleusung in the production process are fundamentally different, so that here fixed combinations of different width static and dynamic classifier can be used. The viewing spaces of the static and dynamic stages are then connected via transition pieces if necessary.

The more the ventilation floor 1a is ventilated, the flatter it can be installed. Taking into account the usual demand for visible air and the material flow behavior, it is preferable to use an inclination of approx. 45 ° + -10 °. The air outlet speed from the aeration floor is chosen so high that the feed material is predominantly held in suspension and only the coarse material touches the ventilation floor. This also prevents the material clogging the ventilation holes and deposits. To achieve this, air velocities should be set at the outlet openings 1b of the aeration bottom of at least 20 m / s, preferably 30 m / s.

The static-dynamic classifier according to the invention is characterized by a high visual efficiency and, in comparison to the known cascade classifiers, requires a substantially smaller structural height, which saves costs.

Claims (9)

1. Static-dynamic sifter for sifting (100) charge material, having

   a. a static sifter (1) which has an aerating base (1a) oriented at an angle relative to the vertical and through which sifting gas (2) may flow,

   b. an inlet opening (3) for delivering the charge material (9) to the aerating base (1a),

   c. an outlet opening (4) for the coarse material,

   d. a dynamic sifter (5), located downstream, which comprises at least one rotor (5a), and

   e. at least one outlet opening (6) for the sifting gas (2') laden with fine material,

   characterised in that
   the aerating base (1a) has a width (b) to vertical height (h) ratio of at least 0.45, preferably of at least 0.6.
2. Sifter according to claim 1, characterised in that a device (101) for uniformly distributing the charge material over the width of the aerating base is also provided.
3. Sifter according to claim 1, wherein disagglomerating means (102) are arranged upstream of the static sifter.
4. Sifter according to claim 1, wherein the width of the rotor (5a) is different from the width of the aerating base (1a), and a housing transition portion is provided between the static and dynamic sifters.
5. Sifter according to claim 1, wherein the surface of the aerating base (1a) is planar and is provided with aerating openings (1b).
6. Sifter according to claim 1, characterised in that the aerating base (1a) is at an angle of from 20° to 70°, preferably from 30° to 60°, relative to the vertical.
7. Sifter according to claim 1, wherein the aerating base (1a) is in such a form that it produces a pressure drop of from 2 mbar to 8 mbar, preferably from 3 mbar to 4 mbar.
8. Sifter according to claim 1, wherein the aerating bases (1a) of devices within a line for different throughputs differ from one another only in terms of their width (b) and not in terms of their vertical height (h).
9. Milling installation having a device according to one or more of claims 1 to 8 as well as a material bed roller mill.

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