FI91368C - Drum Screen - Google Patents

Abstract

The subject of the invention is a drum screen for conditioning and classifying granular material with an input device at the one end of the drum which rotates about its lying longitudinal axis and an output device for the conditioned material at the other drum end. The output device connects to an annular space which is formed between the drum and annular screen sections which are located one after the other in the longitudinal direction of the drum and concentrically surround the drum. The mesh width of the annular screen sections changes in such a way that the section with the smallest mesh width is the annular screen section nearest to the output device and the section with the largest mesh width is the annular screen section at the greatest distance from the output device, preferably located in the region of the input device. Between every two successive annular screen sections (7a, 7b), a channel-shaped profile (29), with the open side directed outwards, concentrically surrounds the drum (2) at a distance of the width of the annular space. The profile engages with a number of hook- shaped mounting elements (28), distributed over the circumference, over the respective profile flange of the annular screen sections ending at it, the annular screen sections being located with initially still extended hook parts (28b) essentially free of play between two channel profiles spaced in the longitudinal direction of the drum and being held after installation in the installation position with the hooks bent about the free flange ends during installation. <IMAGE>

Description

i 91368

The invention relates to a drum screen according to the preamble of claim 1.

Such drum screens are used, for example, to make paving material using bitumen or asphalt and crushed stone with varying grain size. Coarse crushed stone is used for the support layer and fine-grained crushed stone is used for the partial filling of the spaces of the support layer and the bitumen penetrating the permanent spaces acts as a binder for the other parts of the layer. Drum screens of the type 15 can then be used to bring the various components into the correct mixing ratio and in particular to prepare them by tempering in a heated drum screen when the individual coating components have to be applied to the roadbed simultaneously.

20

The object of the invention is to provide a device according to the species so that separate ring screen compartments can be connected to the drum in a particularly expedient manner. By "in a particularly appropriate manner" is meant in particular that the ring screen compartments can be installed and dismantled as quickly as possible and with the minimum of labor required, and that the installed ring screens are reliably connected to the drum when installed.

The solution to this object is served in particular by the features of claim 1, wherein the features by which this solution is expediently applied are the subject of the dependent claims.

In a further variant of the invention, it is necessary to improve the preparation of the mixing material, and as a solution to this sub-task it is provided that the entire drum, including the screens, is provided with a longitudinal axis inclined with respect to the horizontal.

The invention will now be described in more detail with reference to the accompanying drawing, in which:

Fig. 1 is a schematic side view of a mixing groove into which used asphalt is fed during the preparation of a road surface, which, however, is not essential for the invention 10;

Figure 2 is a part of Figure 1 with more details; Fig. 3 is a section along the line III-III in Fig. 4; and

Figure 4 is a side view of the arrow C direction in Figure 3.

The fixed body 1 has a drum 2 rotatably mounted about its longitudinal axis 3. The drum 2 extends from the left end shown in the figure to a burner 4, the longitudinal axis of the flame of which coincides with the longitudinal axis 3 of the drum 3. The burner can in principle be min. The drum 2 is driven by a motor (not shown) via a gear which comprises a running ring 5 permanently connected to the drum surrounding it, and at the lower end of the body 1 there are several so-called treatment silos 6, arranged in the longitudinal direction of the drum in succession. These heating silos are, in addition to 30 heat radiation, well-insulated funnel-shaped silos which receive the crushed material from the drum 1 screened with different coarseness mixed with asphalt or bitumen and which pass it on to the conveyor belt for further processing.

In order to perform the sorting of the material, rotary screens 35 91368 3 7 are arranged on the drum in the longitudinal direction of the drum so that there is a ring space 8 between the casing of the drum 2 and the rotary screens 7. The rotary screens have different mesh sizes. at the end, a small-mesh round mesh screen 7d at the left end of the drum 2 shown in the drawing. The ring space 8 communicates through openings 9 in the interior of the drum 2, which openings are evenly distributed at the left drum end of the drawing on the circumference of the drum.

10

When operating the plant, 2 different substances are now fed to the drum from each end of the drum with the respective feeder devices 10 and 11. towards the flame of the burner 4 whereby it heats up to the desired temperature of the patient. Asphalt used in the drum is fed through the feeding device 11 at the end of the drum burner 4. The mixture of as-20 Falt and crushed stone used enters the ring space 8 through the openings 9 and from there, sorted into the respective crushed stone size, to the heating silos 6, from where it can be taken for further processing.

25 The removal of poles and moisture takes place via the discharge flue 19 at the end of the drum feeder.

The attachment of the central rotary screens 7 to the drum 2 takes place according to the invention as shown in Figures 2 to 4.

30

The pairs of spacers 22, 23 are arranged in areas on either side of the plane 21, which mainly determine the width of the gap between the drum 2 and the rotary screens 7. The pairs of spacing pieces 22, 23 are evenly distributed on the circumference of the drum 2 35, maintaining great distances. Each spacer piece 22 or 23 is a longitudinally shaped profile of the drum having a U-shaped cross-section, with each spacer of a pair of 4 spacers, maintaining a relatively small distance in the circumferential direction of the drum, facing each other on opposite backs 24. attached from its radial inner flanges 25 to the drum 5 2. The length of each distance piece (shape profile) 22 or 23 corresponds approximately to the length of one of the rotary screens 7. A track support 26 is arranged between the "one" distance piece 22 of the distance piece pair and the "second" distance piece 23 of the next distance piece pair in the circumferential direction of the drum 2. one end is fixedly connected, in particular welded, to the "one" of the aforementioned paired distance caps-15 pieces, and the other end is "to the other" to a U-shaped distance piece in cross section. Above these flat, rectangular cross-section sieve supports and on top of the outer flanges 25a of the spacers 22, 23. The Py-20 needle screens are held in this position at each end by a tensioning strap 27. Each tensioning strap is a spring-loaded strip running parallel to the circumference of the drum 2, the length of which is adjustable from the end of the tongue to the tongue. screening outside. Evenly distributed over the length of each tensioning strap, in the initial situation there is an angular holder 28. The horizontal branch 28a of the respective holder is fixedly connected to the tensioning strip 27, for example 30 welded. The second rake 28b is directed radially outwards as a flange-like portion and can be functionally considered as part of the annular screen after the tensioning rim 27 has been inserted and tightened.

Between each of the two screen supports 26 arranged symmetrically with respect to the plane 21, a shape profile 29 running parallel to the circumference of the drum 2 is held, which likewise has a U-shaped cross section 5 91368. This profile 29 is fixedly connected to the screen supports on both sides, in particular welded.

To install the rotary screen, the drum 2 is welded to the splice pieces 22, 23, the screen supports 26 are welded to them, and the profile profiles 29 are welded to the drum 2. The drum 2 thus manufactured is now placed on both sides of the profile 29, i.e. placed in the longitudinal direction per one of the pyro screens between the two contour profiles 29. Thereafter, the clamping strap 27 is placed on both ends of the respective screen with the holding means 28 and pulled on. Thereafter, the radially inwardly directed holders 28 are located as unobtrusively as possible against the shape profile 29. The material of the holders 28 now allows the radially projecting ends of the radially outwardly extending arms 28a (Fig. 3, left) over the flanges of the profile 29 to be bent over the upper edge 20 of the profile 29 flange (Fig. 3, right), thereby tightening the screens are securely attached to the drum 2.

In the described embodiment according to the invention, it is possible to install and disassemble and to change the screens in a simple manner and still place the screens reliably in place without special aids.

Thus, two other features with which the invention is provided serve to improve the use of the drum screen thus installed.

On the other hand, the drum screen as a whole is inclined with respect to the horizontal plane 30 so that an angle α remains between it and the longitudinal axis 3 of the drum so that the discharge end 35 is higher than the inlet end with the feeder 10. This process promotes and the material obtains a radial motion component.

On the other hand, a multi-threaded screw 31 is arranged in the ring space between the drum and the screen or successive screen compartments with different mesh sizes. A trough is arranged between each of the two screw threads for each outlet 9. This means or follows the leveling of the material in the ring space, which promotes sorting and the yield of sorted material in the heating silos 6. Preferably, four outlets 9 and four screws 4 are provided.

At the end of the drum, one flange of the U-shaped profile 29 of cross-section is used either as described, or instead of the arrangement shown in Fig. 3, only half moves to the right or left of the plane 21, depending on whether the drum in Fig. 1 is left or right.

Claims (11)

A screen drum for the conditioning and classification of grainy goods, comprising a feeding device (10) at one of the rotating drum (2) rotating around its longitudinal axis (3) and a dispensing device (9) for the conditioned goods at the second drum spirit, wherein the dispensing device communicates with a ring space (8) formed between the drum (2) and in the longitudinal direction of the drum 10, the drum concentrically surrounding ring sight portion (7), the mesh size of ring screen portion (7) varying such that the section (7d) with the smallest mesh size is the ring screen section closest to the output device (9) and the section (7a) with the largest mesh size is the ring screen section located furthest away from the output device (9), preferably in the area of the input device (10). , characterized by the fact that the longitudinal axis (3) of the drum is slightly inclined to the horizontal plane (30), and that between each two on each other The following ring sieve sections (7a, 7b) have been laminated a concentric drum (2) surrounding gap, in which a robbery string profile (29) is provided with the open side outwardly, each having a retaining means (28) for the ring sieve sections. towards their exteriors with a flanged radially outwardly directed section (28b), which, after incorporation of the ring in question, protrudes first in straight from above the profile, so that with the over-profile projecting section it has been bent around one of the profile edges and applied against the connecting surface of the strand profile, so that the annular section section is hook-shaped over the profile. 2. Screen drum according to claim 1, characterized in that each ring screen section (7a, 7b) on both sides of a robbery string profile (29) abuts on a screen support (26) which encloses the drum and lies in the same circumferential plane as the life of the straw profile. 10 3. Screen drum according to claim 1, characterized in that each ring screen section (7a, 7b) is fixed to its screen support (26) with a closed chip band (27). Screen drum according to any one of claims 1-3, characterized in that hook-shaped retaining means (28) which mesh with the strand profile (29) are fixed to the chip band (27). 5. A screen drum according to any one of claims 1-4, characterized in that the screen supports (26) are fixedly connected to the strand profile (29) on both sides of the strand profile (29) and are located under intermediate coupling of the spacer holders (22, 23). against the drum wave. 15 6. Screen drum according to claim 5, characterized in that the spacer pieces (22, 23) are, in cross-section, robbery strand profiles, which with the inner flange (25) are against the drum (2) and lie in slots between the screen portions (26). 20 Sieve drum according to any one of claims 1-6, characterized in that a multi-purpose transport key (31) is arranged in the annular space between the drum (2) and the ring screens (7), which slug is firmly connected to the drum. 25 Sight drum according to claim 7, characterized in that the drum has an outlet opening (9) for each entry in the transport key. A sight drum according to claims 7 and 8, characterized by four snake inputs and four outlet openings (9). Viewing drum according to claim 1, characterized in that the angle of inclination is in the region of about 10 °. 35 Viewing drum according to claim 1 or 10, characterized in that the boundary line of the angle of inclination (a) lies in the region of the delivery side of the drum (2).