EP0168495B1 - Sieve device - Google Patents

Abstract

The sieve device is used as a feeder and separator of materials which are difficult to separate such as household refuse, industrial waste, cumbersome or dry waste. In order to achieve an optimun distribution and cleaning effect, there are provided two superposed screen sieves (12, 13) comprised of overlapping bars having a conical cross-section and which are free at their ends. The cleaning effect of the device is improved by the step offset of the sieves (12, 13) and by the circulation effect resulting therefrom. The oscillation motion is obtained by means of oscillating elements made of rubber and by an uneccentric drive.

Description

The invention relates to a feed device and screening device for the treatment of valuable materials, domestic waste, commercial waste, bulky waste, dry waste, wet waste, compost and / or problematic and hazardous substances as a ballast to a sorting system, with floating in the direction of transport and open to the end, inclined and rods which can be set into an oscillating movement and which form at least two rod grate sieves arranged one behind the other in steps.

The applicant's EP-A-0 123 825 to be taken into account in accordance with Art. 54 (3) EPC relates to a sorting system for sorting valuable materials, in particular dry waste such as glass, cardboard, paper, plastics or the like. The sorting system consists of several manual and mechanical ones Sorting workstations or stations in which the valuable materials are separated depending on their nature and separated into components.

However, the dry waste, which is heavily clumped and entangled with one another, cannot be thrown directly onto a conveyor belt and thus onto a sorting system. Rather, it appears to be indispensable to supply the dry waste to the system via a feed device which loosens the clumped and devoured waste. On conventional flat screens, the non-uniformly generated dry waste cannot be distributed or loosened to the required extent, since the screen surfaces tend to clog.

From the publication "Processing Technology", Volume 22, No. 7, July 81, pages 395 to 397, a device according to the preamble has become known. The operation of this device is based on the principle that no sieve bed is allowed to form, i. H. the inclination of the rods and the rod spacing are dimensioned such that the material immediately falls through the highly divergent sieve rods arranged one above the other.

From the still known publication US-PS 22 90 434 a device has become known, which also largely relates to the features of the generic term of the present invention. In this known device, the material is fed onto a very short feed plate without any distribution function on bars, which are combined in pairs and constructed in several individual sections.

Finally, from DE-B-1-173 317 a sieve device has become known which has stepped oscillating gratings with tapered and freely floating in the direction of transport, which is open at the end, inclined rods, which serves to convey entangled chips and sieves of short chips and chip fragments.

The known devices have the disadvantage that an effective pretreatment of a heavily clumped and intrinsically entangled dry waste for the task on a sorting device can not be accomplished or only insufficiently.

The invention has for its object to provide a device which is used in particular as a feed device with a distributor function and a screening device for the treatment of valuable materials from domestic waste, commercial waste, bulky waste, dry waste and / or problematic and hazardous substances. The object of the invention is in particular to loosen or distribute the heavily clumped and entangled dry waste coming from refuse collection vehicles in such a way that it can be used in subsequent treatment stages. Small parts are to be screened out.

This object is achieved on the basis of a device of the introductory type according to the invention by the characterizing features of claim 1.

According to the characterizing features of claim 1, it is important in the present invention that the oscillating movement is carried out as a circular oscillating movement with a large amplitude, caused by an eccentric drive, since by this, as well as the natural oscillating movement of the rods, the distribution or loosening effect of the invention solidified dry waste takes place. This oscillating movement is promoted by the rubber oscillating elements according to the invention in cooperation with the eccentric drive. It is important that both the bar grate screen and the pre-distributor section are set into a circular oscillating motion with a large amplitude.

The device according to the invention creates a feeding and screening device for treating valuable materials, as can be used, for example, in connection with the subject matter of patent application EP-A-0 123 825. For example, the dry garbage delivered in the container vehicles, with a wide variety of compositions, can first be placed on the device according to the invention. The combination of the features according to the invention results in a sieving effect of small parts and a cleaning effect of the bar grate sieve, which is better than in the case of known drum sieves, in which there is a permanent shifting of the sieved material. Drum sieves are unsuitable for the task at hand because there is an increased risk of clogging due to the constant layering of the material to be sieved, and because the high drop height, for example, shatters glass. In addition, the advantage of the flat screen with a large receiving area, ie a large screen area, is maintained. Due to the inventive design of the device By means of a vibrating pre-distribution section, the parts come to rest flat before they reach the bar grate. As a result, the parts do not fall directly onto the first bar grate, so that they cannot clog or the parts cannot fall through the screen openings with their narrow sides. Accordingly, only essentially small parts fall through the grate.

Optimal self-cleaning of the device is achieved by the bars tapering in the transport direction and clamped on one side. This applies in particular to materials without internal strength, such as stockings, cords, fabrics, foils, etc., which normally clog the screens slightly. Such materials cannot easily slide through the bar grate screens according to the invention, but are simply pushed off at the free end of the screen bars.

The discharge step and the associated turning process from an upper bar grate screen to a further pre-distributor surface of a further bar grate screen underneath are also decisive, whereby an effect similar to that of the drum screen can be achieved without the disadvantages mentioned above. Of course, several such discharge stations can be provided to circulate the material to be processed, i. H. the screening device is constructed in a step-like manner. However, the impact process is carried out in a dampened manner so that no damage to the valuable materials occurs.

In the subclaims, further measures for solving the problem according to the invention and in particular for advantageous further development and improvement of the device according to the invention are provided.

According to the design according to subclaims 2 and 6, rods with a prismatic, in particular trapezoidal cross-section are used which have a free-extending grate cross-section which widens downwards, the narrow prism side of the trapezoid being arranged at the bottom. This allows the pieces to be screened to slide more easily through the grate d. H. the tendency to constipation is reduced. In conjunction with the conical design in the longitudinal direction of the rods according to subclaim 6 and the formation of free-floating ends, an extraordinarily good screening effect is achieved. This is supported by the additional oscillating movement of the device and the resulting natural vibrations of the rods.

According to the embodiment of the invention according to subclaim 3, a pre-distributor section is connected upstream of the lower bar grate sieve, which is also set into an oscillating movement. As a result, the material to be screened can be distributed evenly in order to reach the subsequent bar grate screen. Furthermore, the distribution function of the feed device is improved.

The development of the invention according to subclaim 4 provides a favorable ratio between the support width of the sieve bar in relation to its projecting length.

The development of the invention according to subclaim 5 prevents the falling material from getting stuck in the rod grate sieve underneath or falling through with the narrow side.

The advantageous development of the invention according to subclaim 7 improves the good distribution effect even on the lower rod grate screen. As a result, the screenings are circulated like a drum screen.

According to the design according to subclaim 8 or 9, the bars are formed with a profile cross section, whereby the free grate cross section also widens downward. This also allows the pieces to be screened to slide more easily through the grate, i.e. H. the tendency to constipation is reduced.

However, it is also provided that the bars in their lower region have projections which protrude into the free grate cross-section, on which flat material is supported and does not fall through the sieve (claim 8).

In conjunction with the conical design in the longitudinal direction of the bars and the free-floating ends, and a preferably zigzag-shaped design of the bars in the longitudinal or transport direction (dependent claim 10), an extraordinarily good screening effect is achieved. The zigzag-shaped design of the rods in particular causes paper goods to be retained. This is supported by the additional oscillating movement of the sieve device and the resulting natural vibrations of the rods.

• Fig. 1 eine Seitenansicht,
• Fig. 2 eine Draufsicht der erfindungsgemäßen Vorrichtung.
• Fig. 3 einen Teilschnitt durch die Stäbe des Stangenrostsiebs.

An advantageous and expedient embodiment of the invention is shown in the drawing and explained in more detail in the following description. Show it

• 1 is a side view,
• Fig. 2 is a plan view of the device according to the invention.
• Fig. 3 shows a partial section through the bars of the grate screen.

The device 10 shown in the figures consists of a screen box 11 in which an upper bar grate screen 12 and a lower bar grate screen 13 are arranged. The complete sieve box with bar grate screens has an inclination angle of α ∞ 3 to 4 °, so that the bar grate screens are slightly inclined downwards in the transport direction.

The inlet area 14 of the device is followed by a pre-distributor section 15 on which the material to be screened can be distributed over the entire width of the device 10 and laid flat. The inlet area 14 and the pre-distribution section 15 take up about 1/3 of the total length of the device 10.

The pre-distribution section 15 follows the upper one Rod grate sieve 12. The rod grate sieve 12 is formed by individual rods 16 arranged parallel to one another, which are firmly clamped in their area 17 facing the pre-distributor section 15. The other end 18 lying in the transport direction, on the other hand, is free-floating, that is to say open, without attachment. The individual rods 16 are prismatic and taper towards the front end 18, the tapering taking place both in a top view and in a side view. In addition, the prismatic cross-section of the rods 16 is designed such that the free grate cross-section widens downward, ie the narrow prism side of the rods is arranged at the bottom (shape of a trapezoid upside down). As a result, as well as the conical design in the longitudinal direction of the rods, the material to be screened can pass through the grate more easily and cannot become jammed. The cleaning effect is therefore significantly increased. In addition, the natural vibration behavior of the rods is positively influenced by the decreasing cross section, so that the cleaning effect is increased. A T-shaped profile is also suitable.

It is often desirable that flat material such as newspapers, sheets of paper or the like not fall through the sieve. For this purpose, projections 28 in the form of, for example, a continuous strip 28 are provided in the lower region 26 of the rods 16, which protrude into the free grate cross section 27. For example, a sheet 29 sliding into the screen gap 27 is blocked from slipping so that it remains on the screen again due to the shaking movement and does not slip (see FIG. 3).

The shrinking cross-section has a positive influence on the natural vibration behavior of the rods, so that the cleaning effect is further increased.

Below the upper bar grate screen 12 there is a further pre-distributing section 19 for the lower bar grate screen 13 adjoining it. The material falling through the upper bar grate sieve 12, however, is distributed from the lower pre-distributing section 19 to the subsequent lower bar grate sieve. However, it can optionally also be discharged from the device at this point.

The last quarter of the upper rod grate sieve 12 overlaps with the first quarter of the lower rod grate sieve 13. Decisive for the good distribution effect and an optimal cleaning effect or sieve effect is u. a. the damped falling process from the end region of the upper bar grate screen 12 onto the distributor section in front of the lower bar grate screen 13. As a result, the material to be screened is circulated like a drum screen.

The lower bar grate sieve 13 is basically constructed in the same way as the upper bar grate sieve 12. The conical design and the free-floating end of the rods, at the ends of which the coarse material falls into a coarse material outlet 20, are decisive.

The coarse material remaining on the grate bars 12, 13 is fed to a coarse material outlet 20 at the end of the device 10, from where it is used for further processing, e.g. B. can be fed in the sorting system. The fine material sifted out through the rod grate sieves 12, 13 is discharged via the outlet 25 and treated separately or is sent to a landfill.

In Fig. 1, the drive mechanism of the device is also shown. The entire screen frame 11 is arranged on maintenance-free rubber vibrating elements 21. Such elements are advantageous for the principle according to the invention, since the most varied vibrations can be carried out by means of an eccentric drive 22 via a motor 23. Due to the one-sided mounting of the bars of the bar grate sieves 12, 13, they additionally carry out their own oscillating movement, which likewise has an advantageous effect on the further transport and sieving of the material to be sieved and on the cleaning effect. The optimal size of the oscillating movement and the oscillating frequency is selected in a manner known per se, depending on the material to be screened.

A baffle plate 24 is provided in the region of the discharge section from the upper bar grate sieve 12 to the lower bar grate sieve 13, which prevents the falling material from getting stuck in the bar grate sieve underneath or falling through with the narrow side.

The alternative design of the bars in a zigzag shape, not shown in the drawing, improves the undesired slipping behavior of paper-like material or the like. For this purpose, the bars are each zigzag-shaped at an angle of, for example, 5 to 10 ° to the transport direction angled, for example to a length of 20 cm.

Claims (10)

1. Feed apparatus and sieve apparatus for the treatment of recoverable materials, household refuse, industrial refuse, bulky refuse, dry refuse, wet refuse, compost and/or substances causing problems and risks, as a preliminary apparatus to a sorting installation, comprising bars that are inclined, open towards the end and freely suspended in the direction of conveying and which can be set in an oscillating movement, which bars constitute at least two bar sieves disposed stepped one behind another, characterized in that a sieve frame (11) having an angle of slope a of from 3° to 4° and mounted on rubber vibration supports (21), comprises an upper, predistributor zone (15) with inlet zone (14), followed by an adjoining bar sieve (12,13), wherein the predistributor zone (15) with inlet zone (14) occupies approximately one-third of the total length of the sieve apparatus (10), that the bar sieves (12, 13) comprise bars (16) tapering in the conveying direction and that an eccentric drive (22, 23), having a large circular oscillation diameter of approximately 100 mm, is provided for the sieve frame (11).

2. Apparatus according to Claim 1, characterized in that the bars (16) have a prismatic cross-section, with a free sieve cross- section which diverges downwards, especially a trapezium-shaped cross-section having a lower short base.

3. Apparatus according to Claim 1, characterized in that a predistributor zone (19) for the lower bar sieve (13) is disposed beneath the upper bar sieve (12).

4. Apparatus according to Claim 1, 2 or 3, characterized in that the ratio of the bearing width of the sieve bar (16) to its cantilevered length lies in the range between 1:50 and 1:100.

5. Apparatus according to Claim 1 or 3, characterized in that a baffle-plate (24) is provided in the region of the discharge zone from the upper bar sieve (12) onto the lower bar sieve (13).

6. Apparatus according to Claim 2, characterized in that the taper of the bars (16) occurs both in plan and in lateral elevation.

7. Apparatus according to Claim 3, characterized in that the predistributor zone (19) for the lower bar sieve (13) extends beyond the end region (18) of the upper bar sieve (12).

8. Apparatus according to Claim 2, characterized in that bars (16) having a trapezium-shaped, rectangular (25) or T-shaped cross-section are provided, which possess in their lower region (26) projections (28) extending into the free crosssection (27) of the sieve.

9. Apparatus according to Claim 1, characterized in that the bars (16) have the cross- section of a T-profile.

10. Apparatus according to Claim 1, characterized in that the bars (16) have a zigzag shape in the direction of conveying.

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