DE29810885U1 - Screening plant - Google Patents

Description

FILE No.

Your sign

PATENT ATTORNEYS

32/37835-001

ROLF BOCKERMANN
DIPL-ING.

PETER KOLL
DR-ING. DIPL.-ING.

APPROVED BY
EUROPEAN PATENT OFFICE
EUROPEAN PATENT ATTORNEYS MANDATES AGREE EUROPEEN

EUROPEAN TRADEMARK ATTORNEYS

Bergstrasse 159
44791 BOCHUM

PO Box 1024 50 44724 BOCHUM

17.06.1998 XK/Mo

Neuenhauser Maschinenbau GmbH & Co. KG Ladestrasse 5, 49828 Neuenhaus

Sieve system

The invention relates to a screening plant according to the features in the preamble of claim 1.

Screening systems are used to separate solid granular materials according to grain size. They are used, for example, in the screening of compost, in the processing of residual waste, for bark mulch, mixed construction waste, rubble and excavated earth.

Screening plants of known design are known, among others, from EP 0 635 313 Al or DE 93 07 096 Ul.

The most important parts of a screening system are the screens, which are used to separate the grains. The screen deck (screen bottom) is the actual working surface of a screen. It can be made of perforated sheets, wire mesh, profile bars

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or consist of rotating sieve elements such as discs or stars.

Another important system component is the feeder through which the screening system is fed with screening material. The aim is basically to achieve a metered feed. This can prevent blockages and even out the flow rate. This prevents unnecessary downtime and increases screening throughput.

However, in operation, a dosed feed is often difficult to implement, since the screening material is fed into the screening plant by wheel loaders. The screening material is usually fed from the wheel loader's loading shovel onto the screening deck via a feed hopper. Depending on the loading height, it is then necessary to create a separate loading ramp for the wheel loader.

Another option is to feed the screening plant using a separate conveyor, for example a scraper conveyor with a hopper. However, such a feed conveyor is not always available, especially with mobile or movable screening plants if they have to change location frequently. The transport and installation of the conveyor also involves additional effort and longer set-up times.

Based on the prior art, the invention is based on the object of creating a high-performance screening plant with an improved task, in which in particular set-up and assembly times when moving the plant and for commissioning are reduced.

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

The screening plant then includes a feed hopper with a conveyor arranged in it. The feed hopper can be moved from a standby position on the supporting frame of the screening plant to a working position.

The lowerable feed hopper allows the screening plant to be fed from a low height in its working position. This is advantageous during operation. Additional ramps or similar for feeding are not required.

The conveyor section integrated into the feed through the additional conveyor means that the feed flow is evened out. This contributes significantly to a continuous screening process and an increase in screening throughput.

Another significant advantage arises when transporting the screening plant. The task can now be moved to its standby position on the support frame without any major assembly work. The screening plant is then moved to a new location. Here the screening plant can be put back into operation within a very short time.

An advantageous embodiment of the basic concept of the invention consists, according to the features of claim 2, in that the feed hopper can be pivoted by a four-bar linkage from the standby position to the working position and vice versa.

The feed is pivotally connected to four links mounted in the support frame. Using suitable drive elements, the links are moved and the feed hopper is moved to its respective position, i.e. it is lifted onto the support frame into the ready position

or lowered into the working position by it. Hydraulic cylinders are preferably used as drive elements. The large-volume feed hopper can be lowered hydraulically and, due to the low feed height, can also be easily fed by smaller wheel loaders.

In order to ensure that the screening material is fed in a metered and even manner, a flow equalizer is arranged at the discharge of the conveyor arranged in the feed hopper above its drive drum (claim 3). In practice, the use of a distributor shaft as a flow equalizer is recommended. The distributor shaft is equipped with paddle-like webs or strips on its circumference, which ensure that the flow is evened out and loosened up.

According to the features of claim 4, a screen deck in the support frame can be positioned using centering bolts and can be secured using quick-release fasteners. This allows the screen decks to be changed quickly. Accordingly, the screen system can be adapted to a wide variety of screening tasks within a very short time. The screen system can be converted quickly by changing the screen decks, for example from star screens to disc screens, without any complex assembly work.

According to the features of claim 5, two screen decks with different sized screen openings and/or different types of screen elements are arranged one behind the other in the support frame. This measure allows up to three different fractions to be screened.

Within the scope of the screening system according to the invention, the use of star and disc screens is considered to be particularly advantageous in practice. These ensure a high level of material movement. The material to be screened is

The material is separated by the rotating screen shafts and conveyed to the screen decks. This means that even the heaviest, wet, clayey soils can be separated. The speed of the screen shafts on the screen decks is conveniently infinitely adjustable. This means that the optimal screen setting can be set depending on the material.

A further advantageous development of the general basic idea provides, according to claim 6, that an air sifting system is integrated. The air sifting system can be used to remove film parts and similar light materials contained in the screening material.

The screening is advantageously carried out by blowing and suctioning at the end of the screening section (claim 7). For this purpose, a blower is arranged in the discharge area below the screening deck and a suction device is arranged above the screening deck.

The wind sifting can be switched on if required.

The invention is described in more detail below using an embodiment shown in the drawings. They show:

Figure 1 shows a side view of a screening plant according to the invention with a feed hopper in the ready position;

Figure 2 shows the representation of Figure 1 with an illustration of the settling process of the feed hopper ;

Figure 3 is a vertical cross-section through the representation of Figure 1 along the line A-A;

Figure 4 shows a vertical cross-section through the representation according to Figure 1 along the line B-B;

Figure 5 shows a vertical cross-section through the representation according to Figure 1 along the line C-C;

Figure 6 shows a distributor shaft in elevation;

Figure 7 shows the representation of Figure 6 in side view;

Figure 8 shows a section of the support frame in side view with the centering bolt and quick release;

Figure 9 shows the representation of Figure 8 in vertical cross section and

Figure 10 in plan view, partly in section, a cleaning device of the screening plant.

Figure 1 shows a mobile screening plant 1 with a support frame 3 that can be moved via a tire-equipped chassis 2. Two disc screens 4, 5 are arranged one behind the other in the support frame 3. The screening plant 1 is fed via a feed 6.

Each disc screen 4 or 5 comprises a screen deck 7, 8, which is formed by discs 11 mounted on axles 10 in a frame 9 (see also Figures 3 and 4). The discs 11 of the screen decks 7, 8 are usually made of rubber or steel and are mounted on the axles 10 with roller bearings. The screen decks 7 and 8 are in their high

arranged in a horizontal orientation at different height levels.

The material to be screened reaches the disc screen 4 via a feed conveyor 12 arranged at the rear of the support frame 3 and leading diagonally upwards. The feed conveyor 12 is a belt conveyor.

The disc screen 4 forms a first screening stage, the so-called fine stage, in which a grain size of 0 mm to 12 mm is usually screened. Material of this grain size falls downwards through the screen deck 7 and is removed via a discharge conveyor 13. The screened material is fed to the discharge conveyor 13, which is located transversely to the screening direction, via two feed belts 14 arranged longitudinally below the screen deck 7.

The remaining screening material falls from the disc screen 4 onto the disc screen 5. This forms a second stage, the so-called middle stage. Here, a grain size of, for example, 0 mm to 25 mm is screened. Material of the corresponding grain size falls through the screen deck 8 and is removed via a second discharge conveyor 15. A feed belt 16 is also arranged under the screen deck 8, which feeds the screened material to the discharge belt 15. Oversize grain is conveyed through the discs 11 to the discharge 17. Here the material falls onto an oversize grain conveyor 18 and is discharged.

As can be seen from the sectional views in Figures 3 to 5, the discharge conveyor 13, the discharge conveyor 15 and the oversize grain conveyor 18 each comprise a cross belt 19 displaced in the support frame 3, which is followed by a pivoting discharge belt 20. In Figures 3 to 5, the discharge belts 20 are each shown in their transport position. Here they are in the support frame.

men 3 for transporting the screening plant 1. During operation, the discharge belts 20 are swiveled to the side of the support frame 3. Large cones of material can be achieved by means of the long discharge belts 20.

The feed 6 comprises a large-volume feed hopper 21 with a conveyor 22 arranged therein. The conveyor 22 is a chain scraper conveyor. The feed hopper 21 can be moved from a standby position B on the support frame 3 to a working position A. For this purpose, it can be pivoted by a four-bar linkage 2 3 on the support frame 3. The transfer process is illustrated in Figure 2 in dashed lines.

The four-bar linkage 2 3 has two parallel links 24, 25 on both sides of the feed hopper 21, which are connected on the one hand to the support frame 3 via swivel joints 26 and on the other hand to stops 2 7 on the side walls 28 of the feed hopper 21. The swivel movement of the links 24, 25 for lowering or raising the feed hopper 21 is carried out by hydraulic cylinders 29, which engage cranks 31 of the links 24, 25 with their piston rods 30. The feed hopper 21 can be hydraulically lowered via the four-bar linkage 2 3 and, due to the low feed height, can also be easily fed by smaller wheel loaders.

Support feet 32 are arranged at the end of the feed hopper 21. The position of the feed hopper 21 in the working position A can be aligned and stabilized using hydraulic cylinders 33 of the support feet 32.

At the discharge 34 of the conveyor 22 arranged in the feed hopper 21, there is a distributor shaft 36 above its drive drum 35 as a conveyor flow equalizer.

As can be seen from Figures 6 and 7, the distributor shaft 36 essentially comprises a base body 37, on which paddle-like distributor bars 38 protrude in the radial direction. The distributor shaft 36 loosens the screening material passed under it during feeding and evens out the conveying flow. The screening material then reaches the feed conveyor 12 via the discharge 34, which then feeds the screening material to the disc screen 4.

Figures 8 and 9 show how the screen decks 7, 8 are fixed in the support frame 3. 39 designates a support of the support frame 3. There is a centering bolt 40 on the support 39. The screen decks 7, 8 are aligned in position using the centering bolts 40. For this purpose, corresponding centering openings 41 are provided in their frame 9. During assembly, the screen decks 7, 8 are placed in the support frame 3. The centering bolts 40 come into contact with the centering openings 41. The screen decks 7, 8 are then fixed using quick-release clamps 42, each of which has a clamping bracket 43 that grips over an abutment hook 44 on the frame 9 of the screen decks 7, 8 and is then tightened using a hand lever 45.

In this way, a quick change of the individual screening decks 7, 8 is possible. Accordingly, the screening system 1 can be converted within a very short time and adapted to different screening tasks.

The screening system 1 further comprises a wind sifter system 46, with the aid of which film parts and other light materials contained in the screening material can be removed.

The air sifting takes place at the end of the screening section by blowing the screening material through a screen deck 8 of

- 10 -

fan 47 acting from below. This further loosens up the material already agitated by the rotating sieve elements 11, which makes it easier to remove the light materials. At the same time, suction is carried out by means of a suction device 48 arranged above the sieve deck 8, which is equipped with a corresponding suction fan 49.

Depending on the degree of contamination of the disc screens 4, 5, their screen decks 7, 8 can be cleaned. For this purpose, a cleaning device 50 is arranged below the screen decks 7, 8 and can be moved in the longitudinal direction.

The cleaning device 50 is shown in the illustration in Figure 10. In Figure 2 it is shown in three different positions, at the beginning, in the middle and at the end of the screening section. The cleaning device 50 essentially comprises a cleaning brush 51, which is pivotably suspended in a frame 52 on a carriage 53. A counterweight 54 is arranged in the frame 52 so that the cleaning brush 51 is automatically pressed against the screening decks 7, 8 from below. This results in a height compensation with regard to the screening decks 7, 8, which are at different heights, during a cleaning run. The position of the cleaning brush 51 automatically adapts to the respective height level. Furthermore, the pivotable and limitedly flexible arrangement of the cleaning brush 51 ensures automatic compensation of the diameter reduction of the cleaning brush 51 that occurs during operation due to wear.

A particularly good cleaning effect is achieved if the rotational movement of the cleaning brush 51 is directed opposite to the rotational movement of the disks 11.

- 13 -

Reference symbol list

1 - Screening plant

2 - Chassis

3 - Support frame

4 - Disc sieve

5 - Disc sieve

6 - Task

7 - Screen deck

8 - Screen deck

9 - Frame

10 - Axis

11 - Disc

12 - Feed conveyor

13 - Discharge conveyor

14 - Feed belt

15 - Discharge conveyor

16 - Feed belt

17 - Discharge

18 - Oversize conveyor

19 - Cross band

20 - Discharge belt

21 - Feed hopper

22 - Sponsors

2 3 - Four-bar linkage

24 - Handlebar

25 - Handlebar

26 - Swivel joint

27 - Stop

28 - Side wall of

29 - Hydraulic cylinder

30 - Piston rod

31 - Crank

32 - Stand

33 - Hydraulic cylinder

34 - Drop

35 - Drive drum

36 - Distributor shaft

37 - Base body

38 - Distribution strips

39 - Carrier

40 - Centering bolt

41 - Centering hole

42 - Quick release

43 - Clamping bracket

44 - Abutment hook

45 - Hand lever

46 - Wind sifter

47 - Blower

48 - Extraction device

49 - Suction fan

50 - Cleaning device

51 - Cleaning brush

52 - Frame

5 3 - Carriage 54 - Counterweight

A - Working position &ngr;.

B - Ready position &ngr;. 21

Claims (7)

- 11 - Protection claims 1. Screening system which has at least one screen deck (7, 8) in a movable support frame (3), with the feed (6) for the material to be screened and a discharge (17) for oversize grain that has not been screened, characterized in that the feed (6) comprises a feed hopper (21) with a conveyor (22) arranged therein, wherein the feed hopper (21) can be moved from a standby position (B) on the support frame (3) into a working position (A). 2. Screening system according to claim 1, characterized in that the feed hopper (21) can be pivoted from the standby position (B) into the working position (A) by means of a four-bar linkage (23). 3. Screening system according to claim 1 or 2, characterized in that a conveyor flow equalizer (36) is arranged at the discharge (34) of the conveyor (22) above its drive drum (35). 4. Screening system according to claims 1 to 3, characterized in that the screen deck (7, 8) in the support frame (3) can be oriented in position by means of centering bolts (40) and can be fixed by means of quick-release clamps (42). 5. Screening plant according to one of claims 1 to 4, characterized in that in the - 12 - Support frame (3) two sieve decks (7, 8) with different sized sieve openings and/or different types of sieve elements (H) are arranged one behind the other. 6. Screening system according to one of claims 1 to 5, characterized in that a wind sifting system (46) is integrated. 7. Screening system according to claim 6, characterized in that the air sifting system (46) in the area of the discharge (17) comprises a blower (47) acting below the screen deck (8) and a suction device (48) arranged above the screen deck (8).