DE2147549A1 - SECURE FOR FINE GRAIN GOODS - Google Patents

Description

Annex to the patent application by

Klöckner-Humboldt-Deutz Mz / Sto 2147549

Corporation

Cologne, 17 September 1971 ^{H 71/39}

Classifier for fine-grained goods

The invention relates to a device for sifting fine-grained substances with the aid of a flowable medium. The device has at least two cyclone-like chambers which are arranged coaxially one inside the other and which are separated from the flowable Medium from outside to inside via at least one inlet opening on the outer chamber and via passage openings flow through the inner chamber. Each of the Kam- * mern shows a good deduction. The inner chamber is additionally provided with a central exhaust pipe for the flowable Medium provided.

A sifter of this type is described in German patent application K 13 155 III / 50 d (published on October 21, 1954). In each of the nested chambers of the classifier, a certain class of grain is separated from the classifier is taken separately in each case. The known classifier is sufficient in terms of the selectivity that can be achieved in it between the The separated grain sizes in the individual grain classes do not meet high requirements, as those taken from the individual chambers Grain classes mutually overlap considerably.

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The object of the invention is to design such a classifier in such a way that a significantly better degree of separation can be achieved leaves.

This object is achieved according to the invention in that the inlet opening of the outer chamber (viewing chamber) is arranged at a distance from the passage so ff openings of the following inner chamber (separation chamber) in the direction of flow, viewed in the axial direction. This measure increases the dwell time for the fine-grained substances contained in the flowable medium in the outer chamber, so that the circulation and drag forces acting on the particles in the cyclone vortex achieve a sufficient sorting of the goods to be sifted in terms of grain sizes before the flowable medium does the fine grain portion of the goods is discharged into the subsequent inner chamber. Each individual chamber can only be taken from certain grain classes determined by the dimensioning and control of the sifter, so that the selectivity of the sifter is considerably refined and the possible uses of the sifter are significantly expanded.

An advantageous embodiment of the invention is achieved by that the viewing chamber in its upper region has a chamber cross-section that widens from its inlet opening has, which extends up to about the height of the passage openings

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extends to the deposition chamber. In the cross-sectional expansion the medium flow slows down in the viewing chamber, the grain band is stretched so that the fluid moves inwards Have entrained grain fractions delimited more finely. According to the invention The desired sharper separation between the individual grain classes is thus further improved.

The cross-sectional expansion of the viewing chamber is generally achieved by a steady increase in the viewing chamber diameter achieved. It is advantageous here that the separation chamber has, above its passage openings, a current-conducting body which is adapted to the widened cross-section of the viewing chamber. The upper area of the sifter is also structurally adjustable to the sifting process and the goods to be sifted, whereby the Effect of the sifter can be optimized. A simple construction of the viewing chamber results when the current conducting body according to of the invention is formed.

Another advantageous embodiment of the invention is characterized in that within the viewing chamber with radial At a distance from the passage openings of the separation chamber, a downwardly open sifter panel is attached. The screen redirects the medium flow again sharply immediately before entering the passage openings of the inner chamber, so that at this point another part of the coarse fraction

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is excreted from the medium. To regulate the coarse grain fraction to be separated in the viewing chamber and for better To adapt the sifter to different goods to be sifted, the sifter screen is useful in relation to the passage openings arranged on the separation chamber adjustable in the axial direction.

The further the screen is lowered in front of the passage openings is, the sharper the flowable medium is deflected before entering the passage openings, the more so the centrifugal force acting on the individual good particles in the flow is greater. The from the flowing medium in The grain fraction entrained in the separation chamber is therefore all the more refined, the deeper the screen in front of the passage openings is lowered. With the help of the adjustable screen, the dividing limit between the in the viewing chamber, or separation chamber to separate out grain fractions to vary with relatively simple means.

As an advantageous structural solution, it is provided that the screen and the current conducting body are firmly connected to one another are, and that the current conducting body is connected to an adjusting device arranged outside the viewing chamber stands. The drive parts of the adjustment device for the screen are thus outside of the dusty atmosphere of the classifier. You are largely protected from soiling.

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The degree of separation for the fine-grain fractions flowing in with the flowable medium is set within the separation chamber supported by the fact that the passage openings with a guide device for generating a vortex flow in the separation chamber are provided. In this case, the separation chamber acts as a cyclone in the same way as the viewing chamber. the The fine grain fractions to be separated are deposited on the walls of the separation chamber and slide through them Downward gravity.

A large number of adjustable guide surfaces are advantageous as guide devices at the passage openings of the separation chamber appropriate. This makes it possible to transfer the flowable medium loaded with the fine material into the separation chamber to direct that the degree of separation is optimized within the chamber.

In a further embodiment of the invention it is provided that the central exhaust pipe used in the separation chamber for the Flowable medium is immersed in the separation chamber and opens below the passage openings. Immersing the flue pipe causes a good formation of the vortex flow within the separation chamber, which leads to the separation of the finest Grain fractions of the goods to be sifted significantly improved. Axial adjustment of the into the separation chamber

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protruding part of the flue pipe, the mouth of the flue pipe can be adjusted to a vortex zone in relation to the immersion depth that is as far as possible freed from the fines. The fines losses of the classifier system are thereby at Suction of the carrier medium reduced to a minimum.

The invention is explained in more detail below using an exemplary embodiment. The schematic figure shows one according to the invention Sifter in section. The sifter shown is intended to separate a material to be classified into two fractions. For the The classifying process is a gas stream as a fluid medium.

In the example, there is an outer Viewing chamber 1 an inner separation chamber 2. Both chambers are designed like a cyclone and coaxially about a common longitudinal axis 3 arranged to each other. Both the Sichckammer 1 and the separation chamber 2 preferably have a circular cross section.

In the viewing chamber 1 opens into an upper inlet opening 4 tangentially a pipeline 5. In the lower area of the viewing chamber 1, a coarse material extractor 6 is arranged, which is connected to a gas-tight Gutaustragsorgan 7, e.g. with a * cellular wheel or with a Flap lock is complete.

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The inner separation chamber 2 is provided with passage openings 8 in its upper area. In the passage openings 8 adjustable guide surfaces 9 are attached as a guide device, which via an adjusting device 10 in their angular position can be regulated from the outside relative to the wall of the separation chamber 2. The separation chamber 2 is down from a Fine art print 11 completed.

The fine material extractor 11 is passed through the viewing chamber 1 and has a material discharge element attached outside the viewing chamber 1 12 provided. A discharge pipe 13 opens centrally from above into the separation chamber 2, the depth of which is immersed via a regulating device 14 can be varied.

The passage openings 8 of the separation chamber 2 are on the separation chamber at an axial distance 15 below the tangential Inlet opening 4 of the viewing chamber arranged. The viewing chamber 1 has in this upper area a tangential one Inlet opening 4 from a constantly expanding chamber cross-section, which extends from the inlet opening 4 to the level of the passage openings 8 extends. In its upper area, the viewing chamber 1 is designed as a truncated cone 16 that is open at the bottom. The viewing chamber 1 is closed at the top by a ceiling 17.

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A rotationally symmetrical current conducting body 18 is attached inside the viewing chamber 1 and is gas-tight at its upper end is passed through the ceiling 17 of the viewing chamber 1. The current conducting body 18 is conical and has approximately the same cone angle as the truncated cone in the upper area of the separator chamber 1. Between the current conducting body 18 and the truncated cone 16, the cross section of the viewing chamber 1 widens.

The cone angles of the current conducting body 18 and the truncated cone 16 can also be chosen so that there is only a minimal cross-sectional expansion results in the upper area in the viewing chamber 1. The cone angle of the current conducting body 18 is then larger selected as the cone angle of the truncated cone 16. This allows the flow velocity of the medium in the upper range the viewing chamber can be kept largely constant, which is before is particularly advantageous when viewing very fine-grained goods.

At the lower edge of the current conducting body 18 is a downwardly open cylindrical screen 19 with a radial spacing 20 arranged in front of the passage openings 7. Via an adjustment device 21, which is attached outside of the viewing chamber 1 and which is connected to the current conducting body 18, can be the viewing screen 19 can be adjusted in the axial direction with respect to the passage openings 8.

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In the present invention, it is de according to the conditions of use for the sifter also possible to equip the Sichterblende 19 and the Stromleitkörper 18 with Se a separate adjusting device, independently to both be able to adjust from one another. With an adjustment of the current conducting body 18, the flow rate in the upper region of the viewing chamber can then be influenced independently of the setting of the separator diaphragm and thus the selectivity of the viewing device according to the invention can be set very precisely.

The mode of operation of the classifier according to the invention is described below described. The fine-grained material flows tangentially within the gas stream via the pipeline 5 and the inlet opening 4 in the upper area of the viewing chamber 1. The cyclone-like design of the Viewing chamber a vertebral depression in which the coarse material migrates to the edge of the viewing chamber, while the finer good particles from the drag forces of the gas flow are carried along and remain in the inner zone of the viewing chamber 1. Due to the substantial Dwell time of the flow of material to be classified in the upper area of the separation chamber and by the expansion of the cross section of the separation chamber results an optimal classifying effect. The coarse grain fraction of the material is deposited on the outer wall of the viewing chamber 1 and falls due to the effect of gravity to the coarse material discharge 6. Below the screen 19, the gas flow is sharply upwards

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deflected and flows with the fine material still remaining in it after the deflection through the passage openings 8 into the inner separation chamber 2.

The extent to which the gas flow is deflected before it enters the passage openings 8 depends on the position of the screen 19 in relation to the passage openings 8. The sharper the curvature of the gas flow, the finer it is Grain fraction that is still entrained into the separation chamber 2 by the gas stream. In connection with the setting of the current conducting body Therefore, the adjustment of the screen 19 causes a shift in the grain class areas, which are still in each case in the separator chamber 1, or in the separation chamber 2 are deposited. The classifier according to the invention is therefore very advantageous to be used in particular in those cases where, depending on the task, it is necessary to either use a certain good different To win grain fractions or to successively add different types of bulk goods in a single classifier treat.

In the exemplary embodiment, the material flow laden with fine material is introduced tangentially through the guide surfaces 9 upon entry into the separation chamber 2 in such a way that a cyclone-like vortex flow also results in the separation chamber 2. In this eddy current exercise, the entrained fine material is separated from the gas flow and removed from the separator via the fine material extractor 11 . To recruitment

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the optimal degree of separation for the fine material in the separation chamber is the exhaust pipe 13 via the regulating device 14 adjustable to the height of the separation chamber 2, in which the gas stream is freed from fine grain as much as possible.

Fans for generating the gas flow in the classifier are not shown separately in the figure. You can act as a pressure generator be arranged in front of the classifier. In most cases, however, they are used as suction fans behind the sifter at & as Flue pipe 13 connected.

To classify a material to be classified into several grain fractions, it is readily possible to use several of the chambers according to the invention to be arranged one inside the other. The inlet opening or the inlet openings of the respective outer chambers are then of the passage openings of the respective inner chambers seen in the axial direction arranged at an appropriate distance from each other. A sufficiently extended residence time results in each of the chambers for the flow of sifted goods, what the selectivity in each Chamber improved accordingly. The direction of the axial displacement between the inlet openings and passage openings can switch from chamber to chamber. An excessive height of a classifier system equipped with multiple chambers can thus be avoided.

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Claims (11)

Claims 1. Device for sifting fine-grained materials with the help a flowable medium, which has at least two coaxially arranged cyclone-like chambers, which of the flowable medium from the outside to the inside via at least one inlet opening in the outer chamber and via a passage flow through openings in the inner chamber, each chamber with an extractor and the inner chamber additionally is provided with a central discharge pipe for the flowable medium, characterized in that the Inlet opening (4) of the outer chamber (viewing chamber) (1) from the passage openings (8) of the inner chamber following in the direction of flow Chamber (separation chamber) (2), viewed in the axial direction, is arranged at a distance (15), 2. Apparatus according to claim 1, characterized in that the viewing chamber (1) in its upper area has a chamber cross-section that widens from its inlet opening (4) which extends up to approximately the height of the passage openings (8) on the separation chamber (2). 3. Apparatus according to claim 2, characterized in that the separation chamber (2) above its passage openings (8) has a current conducting body (8) adapted to the cross-sectional expansion of the viewing chamber (1). - 13 309813/0583 4. Apparatus according to claim 3, characterized in that the current conducting body (18) is conical. 5. Device according to one of claims 1 to 4, characterized in that that within the viewing chamber (1) at a radial distance (20) in front of the passage openings (8) of the separation chamber (2) a downwardly open screen (19) is attached. 6. Apparatus according to claim 5, characterized in that the screen (19) with respect to the passage openings (8) is arranged adjustable in the axial direction. 7 »Device according to claim 6, characterized in that the screen (19) and the current conducting body (18) with one another are firmly connected, and that the current conducting body (18) with an adjusting device arranged outside the viewing chamber (1) (21) is in connection. 8. Device according to one of the preceding claims, characterized in that the passage openings (8) with a Guide device (9) for generating a vortex flow in the separation chamber (2) are provided. - 14 - 309813 / 0S83 9. Apparatus according to claim 8, characterized in that as a guide device on the passage openings (8) of the separation chamber (2) a plurality of adjustable guide surfaces (9) are attached. 10. Device according to one of the preceding claims, characterized in that the central exhaust pipe (13) for the Flowable medium is immersed in the separation chamber (2) and opens below the passage openings (8). 11. The device according to claim 10, characterized in that the protruding into the separation chamber part of the central exhaust pipe (13) is designed to be adjustable with respect to its immersion depth. 309813/0583