EP3305422A1 - Device and method for influencing the movement of a screened material in at least one rotating screen segment of a drum screen machine and its application - Google Patents

Abstract

Device and method for influencing the movement of a Siebguts in at least one screen drum segment (1) a Trommelsiebmaschine, with a plurality on the inside of the Siebtrommelsegments (1) aligned in the axial direction and at equal angular intervals arranged lifting strips (H), each lifting bar (H) a first Section (H1) and a second section (H2), and the second section (H2) is inclined with respect to the first section (H1) at an angle corresponding to the direction of rotation of the screen drum segment (1), or each lever strip (H) is rotated one way of the respective screen drum segment (1) concavely curved shape along a circular path, an ellipse or a spiral and is formed inclined according to the direction of rotation of the screen drum segment (1). The total radial dimension h ges of the lifting bar (H) corresponds to at least one height h s of a Siebgutschicht and / or at least 0.12 times the drum diameter or the largest dimension of Siebgutstückes contained in the screenings with maximum dimensions.

Description

The invention relates to an apparatus and a method for influencing the movement of a screenings material in at least one screen drum segment of a drum screen, and a use.

The influence of Siebgutbewegungen in a Trommelsiebmaschine is usually done on the relative drum speed, which adjusts depending on the speed of either a rolling or a rejecting Siebgutbewegung. The design and dimensioning regulations are predominantly mineral processing and have been adopted for waste treatment. The design and sizing requirements for screening drums and the resulting separation surfaces are mainly based on experience and experimental for the case of municipal waste classification To attempt.

During the rolling screen material movement in a screening drum, the screened material rolls down the sieving slope which adjusts itself, thereby incorporating fines into the resulting structures. Without the release of fines, however, the classification process is disturbed and not functional. The rolling movement of Siebguts should therefore be avoided in principle.

With an increase in the relative drum speed, a rejecting Siebgutbewegung sets. The relative drum speeds are in the classification of municipal waste in the range of 0.45 to 0.6 times the critical drum speed and are technologically limited upwards. In the classification of municipal waste, however, an uncontrolled and undefined Siebgutbewegung arises, which is characterized by a superposition of several states of sliding, rolling and throwing movements. In addition, only a relatively small active separation surface results from the rolling movement.

The process control for municipal waste should be designed in such a way that the transport of fines to the separating surface can be achieved without obstruction by ball or covering of the separating surface by flat pieces.

However, sieve classification of municipal solid waste frequently causes disruption of the classification process up to total failure due to the sieving screen material, especially in the presence of films, textiles, containers or wires.

To reduce entanglements and to influence the passage of screenings through the screen openings cross-sectional extensions, z. B. in the form of sleeves, or adapted geometries of the passage cross-section of the interface used.

Furthermore, internals for Siebgutbeeinflussung and to loosen the screenings in screening drums should not hinder the movement or the passage. However, currently used installations led to a hindrance of Siebgutbewegung or have an unfavorable division in the process area on, resulting in disadvantages.

For example, a drum sifter for classifying wet raw gravel is known, in which the sieve drum is divided into different sections of different sieve opening widths. Here, the screenings are circulated by means of lifting blades in the form of U-profile sections.

In addition, the classification of lumpy municipal waste in Trommelsiebmaschinen is known, are arranged in the inside of a screen drum on a plurality of spars along the entire screen drum conveyor blades. The conveyor blades should be larger than the size of individual pieces of paper or foil in the screenings.

In the prior art, also lifting strips, which are arranged in a screening drum, are described. Moldings for use in the classification of household waste, which loosen and mix the screenings, are formed on these lifting strips.

The use of blades or needles in screening drums for slitting films and containers is also known. In the process, the fines enclosed in the foils or containers are exposed. However, the blades or needles do not affect the movement of the screenings. In addition, pointed objects favor the hooking and hooking of tortuous pieces of screenings or films in the screen drum. The cleaning of such facilities is associated with a considerable effort and with a risk to the staff. The cleaning also causes unwanted and costly downtime of Trommelsiebmaschinen.

The known solutions always focus on the exposure of fines and / or the tearing of films or containers. Targeted movement of the screenings with defined discharge and impact areas within the screen drum is not recognizable in the prior art.

In addition, hitherto used for incorporation of the screen drum are often too small dimensions, so that in the axial direction, either the angular distance between the lifting strips is too large and so the screenings along the Parting surface slides, or the dimensioning in the radial direction is too small, so that during the passage of screenings takes place an overlap of the internals with screenings, resulting in a rolling Siebgutbewegung results.

It is therefore an object of the invention to provide a device and a method that influence the movement behavior of the screenings so that the screenings loosened up, the exposure of fines ensured and the ball formation and coverage of the parting surface can be prevented with flat Siebgutstücken.

According to the invention the object is achieved with a device having the features of claim 1, and a method according to claim 9. A use of the device and the method relates to the claim 10. Advantageous embodiments and further developments are described in the subordinate claims.

A device according to the invention for influencing the movement of a screened material in at least one screen drum segment of a drum screening machine has a plurality of lifting strips aligned in the axial direction on the inside of the screen drum segment, which are arranged at equal angular distances from one another. A screen drum of a drum screening machine is usually formed with a plurality of drum screen segments. For example, the individual segments each have a length in the range of 1 m.

The lifting strips can each be formed from a metal sheet. Through the use of lifting strips, the screenings are forcibly conveyed during the rotary movement of the screen drum segment in the ascent movement up to a discharge point and thrown off there.

Each lift bar has a first portion and a second portion, wherein the second portion is formed inclined with respect to the first portion at an angle corresponding to the direction of rotation of the screen drum segment.

The total radial dimension h _ges a lever bar in the direction of the axis of rotation of the respective screen drum segment corresponds to the sum of the radial portion h _{1, radially of} the height h _{1 of} the first section and the radial portion h _{2, radially of} the height h _{2 of} the second section, where h _{1, radially} > 0 to 0.99 h _ges , preferably between 0.2 h _ges and 0.8 h _ges , and h _{2, radially} > 0 to 0.99 h _ges , preferably between 0.2 h _ges and 0.8 h _ges are.

In an alternative embodiment, each lifting ledge has a concavely curved shape along a circular path, an ellipse or a spiral in the direction of rotation of the respective sieve drum segment and is designed to be inclined in accordance with the direction of rotation of the sieve drum segment. In this case, the oriented in the direction of the axis of rotation front edge of the lifting bar extends beyond a plane in the axial direction of the respective screen drum segment, which is spanned between the base of the lifting bar and the axis of rotation, not.

The overall radial dimension h _ges of the lifting bar in the direction of the axis of rotation of the respective sieve drum segment corresponds to the distance between a plane parallel to a plane extending through the base of the lifting strip tangent of the respective sieve drum segment, which contacts a front edge of the lifting strip, the base of the lifting strip. The front edge of the lifting bar is the edge of a lifting bar facing the axis of rotation of the respective screening drum segment.

The radial overall dimension h _{ges of} the lifting strip also corresponds to at least one height h _{s of} a Siebgutschicht. The filling of the respective screen drum segment is assumed to be a circular segment of the screen drum segment cross section. The total radial dimension h _{ges of} the lifting bar may be alone or additionally at least 0.12 times the inner diameter of the drum drum segment or the largest dimension of Siebgutstückes contained in the screenings having maximum dimension.

The length of the lifting bar in axial alignment in a screen drum segment should correspond at maximum to the length of the respective screening drum segment in order not to project into an adjacent / the adjacent screen drum segment (s), where too long length of the lifting ledges in / in the adjacent Screen drum segment (s) Disturbances in the upward movement of the screenings during the rotary motion of the screen drum segment may occur. In addition, if the length of the strips is too long, the strips protruding into the adjacent screen drum segment (s) may cover part of the area of impact and thus the parting surface in the adjacent screen drum segment (s).

The length of the lifting bar should also not be much smaller than the entire length of the respective screening drum segment in the longitudinal direction, since it should be ensured that the screenings are conveyed over the entire length of the screening drum segment about an axis of rotation of the respective screening drum segment.

In a preferred embodiment, exactly three levers are arranged in the axial direction with an angular distance of 120 ° in the screen drum segment in a screen drum segment. Thus, the impact and discharge areas are optimally distributed in the screen drum segment, d. H. The distribution of the lifting strips is chosen so that during the period of ejection and impact of the screenings on the separation surface of the screening drum segment no lifting bar passes through the impact area.

The first section of the lifting bar may be arranged along a radius in the direction of the axis of rotation of the respective screening drum segment. The second section of the lifting bar should be inclined in the direction of rotation of the screening drum at an angle α ₂ in the range> 0 ° to 45 ° with respect to the first section. This arrangement of the first and the second section, in conjunction with the geometry of the first and second sections, creates a defined discharge area for the screenings from the lifting strip, from which the screenings are discarded individually. The screened material hits the impact area opposite the ejecting lever bar. In this way, a material-specific sliding on the lifting bar in response to the angular position of the lifting bar can be achieved during the rotation of the drum and thus a clear determination of a substance-specific discharge area for the screenings are taken.

The inclination of the second section of the lifting bar relative to the first Section can be achieved by bending the second section and / or by curving the second section along a circular path, an ellipse or a spiral. The lifting bar can therefore also have a combined curved shape. The resulting cross-sectional shape of the lifting bar can influence the sliding of the Siebguts and the discharge time during the rotation of the Siebtrommelsegments.

The lifting ledge may be secured to the inside of the screen drum segment by welding, gluing or positive locking means. The selection of the type of fastening of the lifting strips depends on the material to be screened, the size of individual screenings and the expected mechanical loading of the screen drum segment by the screenings and the relative drum speed to be used.

The screen drum segment (s) of a drum screen machine may be inclined in the conveying direction at an angle in the range of 0 ° to 30 °. Due to the inclination of the screen drum segment (s) in the conveying direction and the rotational movement of the screen drum segment (s), the screenings are conveyed through the screen drum.

In a method according to the invention for influencing the movement of a screened material in a drum screening machine with the described device, the screenings are moved during the rotation of the screen drum segment in the drum screen by means of the lifting strips around a rotation axis of the screen drum segment and the components of the screenings are individually dropped from the lifting strips so that they individually in a defined area lying in the screen drum segment of the respective ejecting lever bar, impinge. The screenings are loosened and exposed in the screenings contained fines.

The apparatus and method described may find use in the classification of municipal waste, in particular in the classification of lightweight packaging, mixed municipal waste and sorting residues.

With the device and the method according to the invention, the active usable separation surface in a screen drum segment are defined and maximized. The optimal dimensioning of the geometric dimensions of the lifting strips and their angular spacing reduces the sliding movement of the screenings on the separating surface. In addition, a sequential discharge, ie a separation of the material to be screened from the inner edge of the lifting bar and a loosening of the screenings can be achieved by the geometry of the lifting strips. At the same time, the exposure of fines can be achieved because, for example, plastic foils can be released from the lifting strip during the flight phase fines with isolated ejection.

By the lifting strips, which are arranged in the respective screen drum segment, the respective impact area of the screenings is cleared of the ejecting lever bar in the direction of rotation of the screen drum segment subsequent lifting bar, so that the discarded screenings impinges on a free area of the separating surface. Thus, a hindrance of the classification can be avoided by lying on the parting screenings. Also, by adjusting the geometry of the lifting ledges and their spacing depending on their number, no obstruction due to disturbing installations in the area of the active parting surface takes place.

At the same time a reduction of the rolling movement of films on the Siebgutböschung and thus a reduction of the ball formation is achieved with the device according to the invention and the associated method.

Figur 1

einen Querschnitt eines Siebtrommelsegments mit einer beispielhaften Ausführungsvariante der erfindungsgemäßen Vorrichtung mit drei Hebeleisten,

Figur 2

eine seitliche Ansicht eines beispielhaften Siebtrommelsegments aus Figur 1,

Figur 3

einen Ausschnitt "A" des Querschnitts aus Figur 1, und

Figur 4

einen Querschnitt eines Siebtrommelsegments mit einer weiteren beispielhaften Ausführungsvariante der erfindungsgemäßen Vorrichtung mit drei Hebeleisten.

Below, the device and the method will be explained in more detail with reference to an example. Showing:

FIG. 1

a cross section of a screening drum segment with an exemplary embodiment of the device according to the invention with three levers,

FIG. 2

a side view of an exemplary screen drum segment FIG. 1 .

FIG. 3

a section "A" of the cross section FIG. 1 , and

FIG. 4

a cross section of a screening drum segment with a further exemplary embodiment of the device according to the invention with three levers.

In FIG. 1 is a cross section of a screening drum segment 1 with an exemplary embodiment of the device according to the invention with three lifting strips H shown. Therein, the lifting strips H are arranged in the axial direction and at a constant angular distance of 120 ° and fastened by means of screws on the inside of the screen drum segment 1. The lifting strips H each have a first section H1 and a second section H2.

The direction of rotation of the screen drum segment 1 about the axis of rotation 2 of the screen drum segment 1 is marked with an arrow and the symbol for the angular velocity ω. Moreover, in FIG. 1 an area "A" marked in FIG. 3 is shown as a detail.

In FIG. 2 is a side view of the exemplary embodiment of a screen drum segment 1 from FIG. 1 shown. Therein, the length of the screen drum segment 1 with l _sec , the length of the lifting strips is denoted by L and the hole width of the screen drum segment 1 with w. In the drawing, above the axis of rotation 2, the attachment region of a lifting strip H can be seen in a plan view. As in FIG. 2 can be seen, the length l _{sec of} the screen drum segment 1 and the length L of the lifting bar H are the same size.

In FIG. 3 is the area marked "A" off FIG. 1 shown as a detail. The first portion H1 of the lifting ledge H is arranged and aligned at a radius in the direction of the rotational axis 2 of the screening drum segment 1. The radial component h _{1, radial of} the height h _{1 of} the first section H1 in this case correspond to each other.

The second section H2 is inclined at an angle of α ₂ = 45 ° against the first section H1 in the direction of rotation. However, the inclination can be selected lower depending on the screenings to be screened and the relative drum speed. The inclination of the second section H2 of the lifting strip H with respect to the first section H1 was achieved by bending the sheet from which the lifting strip H is formed.

The total radial dimension h _{ges of} the lifting bar H in the direction of the axis of rotation 2 of the respective screen drum segment 1 results from the sum of the radial portion h _{1, radially} the height h _{1 of} the first portion H1, which corresponds to the height h ₁ in this example, and the radial portion h _{2 , radially} the height h _{2 of} the second Section H2.

The total radial dimension h _{ges of} the lifting strip H has at least the height h _s , which corresponds to the height of a Siebgutschicht in the screen drum segment 1. The total radial dimension h _ges lifting strip H is also at least 0.12 times the inner diameter of the drum drum segment 1. The total radial dimension h _ges the lifting bar H but also the largest dimension of Siebgutstückes contained in the screenings, in the case of use for the classification of municipal waste of a piece of waste of maximum dimension.

With the device according to the invention shown in the figures, municipal waste is preferably classified.

The screenings, in this example municipal waste, during the rotation of the screen drum segment 1 by means of the lifting strips H forcibly conveyed about the rotation axis 2 of the screen drum segment 1. Depending on the drum speed and the geometry and dimensioning of the lifting strips H, the individual components of the municipal waste are dropped individually from the respective lifting strip H.

The discarded municipal waste meet in a region of the screen drum segment 1, which is opposite to the ejecting lever strip H. The screenings are loosened and fines are released. In addition, during the flight phase, foils and containers contained in the municipal waste are opened, thereby also releasing the fines contained therein.

The lifting strips H are arranged so that the discarded screenings always impinges on a free area of the screen drum segment 1. On the one hand, the lifting strips H following in the direction of rotation cancel out the region of the screening drum segment 1 which lies opposite the ejecting lifting strip H, and on the other hand the division of the lifting strips is selected such that during the period of ejection and impingement of the screenings onto the separating surface of the screening drum segment 1 no lifting bar H passes through the impact area.

FIG. 4 shows a further exemplary cross section of a screen drum segment 1 of the device according to the invention with three strips H. In this embodiment, the three arranged at equal angular intervals H strips H a concave curved shape along an ellipse and are inclined according to the rotational direction ω of the screen drum segment 1. The overall radial dimension h _ges the lifters H corresponds to the distance a parallel P to a plane passing through the base point 4 of the lifting strip H tangent T of the screen drum segment 1, the lifting strip touches H the end edge 3, the base point 4 of the lifting strip H.

Claims (10)

Device for influencing the movement of a screened material in at least one screen drum segment (1) of a drum screening machine, comprising a plurality of lifting strips (H) aligned on the inside of the screen drum segment (1) in the axial direction and arranged at equal angular intervals
each lift ledge (H) has a first portion (H1) and a second portion (H2), and the second portion (H2) is inclined with respect to the first portion (H1) at an angle corresponding to the rotational direction of the screen drum segment (1), and
the total radial dimension h _{ges of} the lifting strip (H) in the direction of the axis of rotation (2) of the respective screen drum segment (1) the sum of the radial portion h _{1, radially} the height h _{1 of} the first portion (H1) and the radial portion h _{2, radially} the height h _{2 of} the second section (H ₂ ) corresponds, where h _{1, radially} > 0 to 0.99 h _tot and h _{2, radially} > 0 to 0.99 h _ges ,
or
each lifting ledge (H) has a concavely curved shape along a circular path, an ellipse or a spiral in the direction of rotation of the respective screen drum segment (1) and is inclined according to the direction of rotation of the screen drum segment (1), the directional axis being in the direction of the axis of rotation (2) Front edge (3) of the lifting strip (H) a plane (E) in the axial direction of the respective screening drum segment (1), which is spanned between the base (4) of the lifting strip (H) and the axis of rotation (2), not surmounted and
the overall radial dimension h _ges of the lifting strip (H) in the direction of the axis of rotation (2) of the respective sieve drum segment (1) the distance a parallel (P) to a through the root point (4) of the lifting bar (H) extending tangent (T) of the respective Screen drum segment (1), which touches the front edge (3), to the foot point (4) of the lifting bar (H) corresponds
and
the total radial dimension h _{ges of} the lifting bar (H) corresponds to at least one height of a Siebgutschicht and / or the radial total dimension h _ges the lifting bar (H) at least 0.12 times the drum diameter or the largest dimension of Siebgutstückes contained in Siebgutstückes with maximum dimensions equivalent. Apparatus according to claim 1, characterized in that the length of the lifting bar (H) corresponds at most to the length of the respective screening drum segment (1). Device according to one of the preceding claims, characterized in that in a screen drum segment (1) exactly three lifting strips are arranged. Device according to one of the preceding claims, characterized in that the first portion (H1) of the lifting strip (H) along a radius of the screen drum segment (1) is arranged. Device according to one of the preceding claims, characterized in that the second section (H2) of the lifting strip (H) in the direction of rotation of the screen drum at an angle α ₂ in the range> 0 ° to 45 ° relative to the first portion (H1) is inclined. Device according to one of the preceding claims, characterized in that the inclination of the second portion (H2) of the lifting strip (H) relative to the first portion (H1) of the lifting strip (H) by bending the second portion (H2) and / or by bending the second section (H2) along a circular path, an ellipse or a spiral is accessible. Device according to one of the preceding claims, characterized in that the lifting strip (H) by welding, gluing or is secured by means of positive connection means on the inside of the screen drum segment (1). Device according to one of the preceding claims, characterized in that the / the screen drum segment (s) (1) is inclined in the conveying direction at an angle in the range of 0 ° to 30 ° / are. Method for influencing the movement of a screened product in a drum screening machine with a device according to one of the preceding claims, wherein during the rotary movement of the screening drum segment (1) in the drum screening machine the screenings are moved about an axis of rotation (2) of the screen drum segment (1) by means of the lifting strips (1) moved and the components of Siebguts individually from the lifting strips (H) are dropped so that they individually in a defined, the respective lifting bar (H) from which the Siebgut is dropped, the opposite region of the Siebtrommelsegments (1) impinges while the Siebgut loosened and contained in the screenings fine material is exposed. Use of a device according to one of claims 1 to 8 with a method according to claim 9 for the classification of municipal waste.

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