EP1144137B1 - Sieving device for solid material and a method for sieving solid material - Google Patents

Abstract

The screening device uses a rod (8) which is wound into a spiral (10). It is rotated is fed into the interior of the spiral, e.g. via a rotary feed drum (2) with the spiral attached to it at one end. The rotary feed drum may be inclined to the horizontal, with the spiral attached to its lower end. The axis of the spiral may be curved downwards due to the spiral weight.

Description

The invention relates to a pyrolysis plant according to the preamble of claim 1.

In many technical fields of application it is necessary that solids contained, for example, in bulk material are divided into several fractions. The factions are usually based on different solids sizes, Solid geometries or textures divided. A separation of the solids is always desirable if the different solid fractions of another Treatment should be administered.

In the construction industry, for example, there is building rubble separated from large and bulky debris, which then sorted and recycled. The separated finer Building rubble is, for example, on a designated one Landfill.

In the field of waste disposal, with regard to a disposal and sorting as environmentally friendly as possible of the waste or that resulting from the recycling of waste Residues are becoming increasingly important. An essential point this is a separation of the waste according to its size. The Separation can be done before recycling the waste become; however, it can also be an essential procedural step be in waste recycling itself.

Thermal processes are known for waste disposal, at where the waste is burned in waste incineration plants or in Pyrolysis plants pyrolyzed, i.e. in the absence of air Temperature from about 400 ° C to 700 ° C is subjected. at Both methods make sense after the combustion or to separate the residue remaining after pyrolysis, to either recycle it or dispose of it in a suitable manner. The aim is to residual material to be disposed of in a landfill as low as possible to keep.

From EP-A-0 302 310 and from the company publication "Die Schwel-Brenn-Anlage, a description of the process ", publisher Siemens AG, Berlin and Munich, 1996, is a pyrolysis plant so-called smoldering plant known, in which essentially a two-step process is carried out. In The first step is the delivered waste in a smoldering drum (Pyrolysis reactor) introduced and charred there (Pyrolyzed). During pyrolysis, the smoldering drum is formed Smoldering gas and pyrolysis residue. The smoldering gas becomes together with combustible parts of the pyrolysis residue in one High temperature combustion chamber at temperatures of approx. 1200 ° C burned. The resulting exhaust gases are then cleaned.

In addition to the combustible parts, the pyrolysis residue also has non-combustible parts. Put the non-combustible parts essentially consists of an inert fraction, such as glass, Stones or ceramics, as well as composed of a metal fraction. The recyclable materials are sorted out and recycled fed. There are procedures for sorting out and components necessary that are reliable and continuous Ensure operation.

The problem with screening devices is often that clog the sieve surfaces. Then the screening device fails, or it must at least be a complex and labor-intensive one Undergo cleaning. The problem of constipation the screening device occurs particularly in the case of a strongly inhomogeneous Composition of the solid to be separated. So for example, wires get caught in screen surfaces Perforated sheets, so that the individual holes first be narrowed and clog up over time.

The residue obtained during pyrolysis is typical such a strongly inhomogeneous solid, which with regard to its material composition, its size and geometry its solid parts shows great differences. In the residue is next to stones, broken glass and larger metal parts also elongated bars as well as in twisted wires (wire bulges).

For the separation of coarse pyrolysis residue is, for example from WO 97/26495 a discharge device for pyrolysis residues known from a smoldering drum. The discharge device includes a conveyor that has a sawtooth profiled partition with an attached Rod screen has. The partition will vibrate offset so that the fine of the separate coarse parts. The fine parts fall through subsequent rod sieve through, while the coarse fractions slide on the bar screen. Wirewalls can however, hang on the poles and cause constipation to lead.

EP 0 086 488 A2 also includes a pyrolysis plant for waste known a screening device for solid, the screening device is rotatable about its longitudinal axis.

FR 27 45 204 A1 also discloses the use a rod wound along a helix at one Screening device.

The present invention has for its object a Pyrolysis plant for waste with a sieve for solid Specify residual material in the case of continuous operation with simple means is guaranteed without constipation occur.

This object is achieved according to the invention by a pyrolysis plant solved with the features of claim 1.

One advantage of a screening device designed in this way is to be seen in the fact that there are no piles of wire or other solid can stick. Because by the rotation the sieve device, the wire crust due to the Rod winding pushed down in the conveying direction. Blockages are thus effectively avoided.

The rod member is substantially parallel to that formed by the spiral outer surface or parallel to the formed by the multi-course screen and acts as a wiping element as follows: a wire bulge gets caught on the pole, this wire bulge is due to the Rotary movement of the sieve against the fixed rod element out and is guided by this along the helix of stripped the rod. To achieve this is the sense of rotation the rod to the direction of rotation of the screening device switched off.

In a preferred embodiment, the rod is a spiral with several turns, in particular with about four to ten Turns, formed.

In such a screening device, which is also called a "spiral screen" can be called the solid to be sieved into the interior formed by the three-dimensional spiral brought in. Fine solid with smaller dimensions as the distance between two turns of the spiral falls through the spiral while coarse solid in the interior is further promoted. By an appropriate choice of Spacing between turns can be the maximum size of the sieved finer solids content can be adjusted. By the rotation of the spiral becomes more secure and continuous Transport of the coarser solid parts in the conveying direction guaranteed from the beginning of the spiral to the end of the spiral.

A major advantage of the spiral is that any waste parts stuck between two turns be lifted up by the rotary movement and in particular fall at the upper turning point due to their own weight. The simple and robust design of the screening device as a spiral, therefore, avoids permanent constipation and enables continuous operation.

A number of rods are in a practical embodiment provided, the rod beginnings arranged rotatably are. Each bar runs along a helix. Such a sieve with several rods is also called multi-pass sieve.

In an alternative embodiment to the spiral screen the angle of rotation of the rods is less than 360 °. In particular is the angle of rotation is less than or approximately equal to 180 °. By design with multiple rods that are not a full turn can perform the screening device compared to one Spiral sieve with several turns can be made more robust.

The rod element is for the most efficient stripping preferably also wound along a helix, and in particular counter to the rod, so that it with the rod, for example, an angle of preferred 90 ° includes.

In a particularly advantageous embodiment, the spiral screen the spiral is attached to only one of its two ends, so that the spiral axis due to its own weight towards its gravity towards its unpaved end is curved below. The spiral is preferred only at the beginning of the spiral held while the spiral end located in the conveying direction is designed to hang freely.

As an alternative to a spiral fixed on one side can also an already curved spiral attached on both sides become. It is essential that the spiral is curved.

The main advantage of curvature is that that the distances of the turns at the bottom of the spiral are smaller than the distances at the top of the spiral. Solid matter introduced into the spiral can in principle only between turns on the lower side of the spiral jam because as soon as it is lifted due to its Dead weight falls down. In other words: through the Spiral movement becomes a jammed solid part with the Spiral raised up. At the same time, the distance is widening of the turns so that the solid part between the turns cannot remain clamped and due to its own weight inevitably falls down. The screening device with curved spiral is therefore highly self-cleaning.

In order to allow the spiral to bend, it is useful to to make the spiral flexible. At the same time this causes tensions caused by trapped solid parts act the spiral, kept low.

This is the spiral for a stable and simple design forming rod advantageously metallic and in particular a round bar or a pipe made of iron or steel. A such a spiral is extremely robust and is particularly suitable also for rough separation of heavy and large solids. For applications in which only low loads are involved occur, the spiral is made of plastic, for example.

In a particularly preferred embodiment is for alignment of elongated solid parts in the conveying direction an alignment device is provided in the screening device, which is arranged in the conveying direction in front of the rod, and the flows into the interior.

The alignment of the elongated solid parts ensures that this is essentially parallel to the longitudinal axis in the interior can be introduced. Elongated solid parts are therefore also automatically as coarse solid parts treated and promoted. You can't be vertical fall through the spiral to the longitudinal axis. Consequently is guaranteed that by the off the shelf or by the The sieve formed from rods only falls through solid particles, whose largest dimension is smaller than the distance two turns of the spiral or as the distance between two Rods.

For easy alignment of the elongated solid parts To ensure the alignment device is as one configured drum rotatable about its longitudinal axis. by virtue of the solid parts are aligned with the rotary movement of the drum automatically in the direction of the drum axis.

The arrangement of a helix on the Inside of the drum, so the arrangement of a helical winding ledge. This spiral prevents that solid, for example, through a feed chute into which one end of the drum is inserted, the drum with a passes through at high speed so that the solid "flies" through the interior space formed by the rod, without screening. Prefers the helix is multi-start, i.e. there are several helical strips are provided, which are rotationally offset are arranged. The helix is particularly immediately on arranged on the inlet side of the drum and has a relative high flank.

The helix is in particular designed such that it - in a plan view seen in the direction of the longitudinal axis of the drum - forms a closed circle. This means that that solids on the drum bottom straight from the drum entrance slide through to the drum exit without any obstacles can. In order not to obstruct the flow of solids unnecessarily, becomes a multi-turn helix with an angle of rotation smaller 360 ° preferred. In this case, the desired overlap the flank reaches and at the same time becomes a relatively flat one Incline of the helix allows for a faster solids transport inside the drum.

In an alternative embodiment, the alignment device as a profiled oscillating floor with longitudinal grooves designed in which the longitudinal grooves in the conveying direction run and in which the elongated solid parts due the vibrations of the vibrating floor in these longitudinal grooves be aligned.

The rod is advantageously on the in the conveying direction end face of the drum attached to this and there especially welded. The rod is preferably attached in such a way that the drum exit in the formed by the rod Interior opens. For a smooth material discharge the rod is out of the drum on the outer wall of the drum or at least attached flush with the drum.

In this constructive configuration form alignment device and rod a particularly simple construction unit, that is robust and reliable.

The screening device is in a particularly preferred embodiment with the discharge side of the smoldering drum of the pyrolysis plant for screening of those obtained from the smoldering drum Pyrolysis residues connected.

With the sieve device is preferred in the pyrolysis plant a first separation of the pyrolysis residue into a fine and made a rough residue fraction. Because of the simple and particularly robust design of the screening device is a safe and continuous operation of the whole Pyrolysis plant ensured.

It is particularly advantageous and expedient to use the screening device directly with the smoldering drum on the discharge side to connect firmly. So are between the smoldering drum and no further components are interposed between the screening device, that can cause interference. The Rod is, for example, directly on a discharge pipe attached to the smoldering drum and within a discharge device arranged. This discharge device is preferred sealed gas-tight from the outside atmosphere to prevent entry to avoid atmospheric oxygen leading to combustion of the combustible and hot pyrolysis residue.

In particular for the purpose of coarse screening of residual material from a industrial pyrolysis plant is the distance between two turns of the spiral or between two rods advantageously about 100 mm to 300 mm and in particular about 180 mm. The interior formed by the rod has one Length of about 0.5 to 1.5 m. Its diameter is about 1.5 m, and a sieve device with drum and sieve preferably has a total length of about 2 to 4 m. The Length of the interior is suitably less or equal to the diameter of the drum.

FIG 1

eine Siebvorrichtung, bei der eine Trommel als Ausrichtvorrichtung mit einer Spirale fest verbunden ist,

FIG 2

einen Schnitt durch eine gekrümmte Spirale zur Erläuterung der vorteilhaften Wirkung der Siebvorrichtung,

FIG 3

eine Schweltrommel mit daran befestigter Spirale, und

FIG 4

eine Siebvorrichtung mit einer Anzahl von Stangen als mehrgängiges Sieb.

The invention and advantageous embodiments are explained in more detail below with reference to the drawing. Each shows in a schematic view:

FIG. 1

a screening device in which a drum is firmly connected as an alignment device with a spiral,

FIG 2

2 shows a section through a curved spiral to explain the advantageous effect of the screening device,

FIG 3

a smoldering drum with attached spiral, and

FIG 4

a sieve device with a number of rods as a multi-start sieve.

According to FIG. 1, a screening device 1 comprises an alignment device, namely a drum rotatable about its longitudinal axis 2, which is inclined to the horizontal. On theirs left end face 4 is a shaft-like feeder 6 arranged for solid R. With this solid R e.g. pyrolysis residue or rubble. On the right of the feeder 6 opposite Front 7 of drum 2 is one along a helix coiled rod 8 made of metal attached to a spiral 10 with an interior 11 forms. The spiral 10 is for example with a suitable welding, screwing or Clamp connection attached to the drum 2. The spiral 10 aligns approximately with the drum 2, so that the diameter the drum 2 and that of the spiral 10 are approximately the same. This allows the entire right face 7 as a drum exit can be used for the solid R, and that the drum 2, for example, as a simple tube made of metal can be designed. The common longitudinal axis 3 of the screening device 1 and the drum 2 essentially falls with the Spiral axis 12 of the spiral 10 together.

The drum 2 is rotatably supported. You can't over one drive shown in detail can be set in rotation. Together the drum 2 also rotates the drum 2 attached spiral 10. This has five turns according to Figure 1 on. The distance between two adjacent turns depends on the type of solid R. It is present preferably about 180 mm. The spiral wound Rod 8 is made of a robust material and is special metallic. For example, it is a round bar or a steel pipe. The spiral 10 is only one-sided, namely on the drum 2 attached. Your spiral end facing away from drum 2 is free of fasteners and is not supported. The spiral 10 will therefore become unpaved Bend downward due to gravity. hereupon is discussed in more detail below in FIG. 2.

The solid R is the feed device 6 in the Drum 2 is given and is due to the inclination of the drum 2nd and the rotational movement in the conveying direction 14 towards the spiral 10 transported. Fine solid F is separated off in the spiral 10, while coarse solid G is transported further by the spiral 10 becomes.

A major advantage of the screening device 1 with the spiral 10 can be seen in the fact that even more fluent Solid R through the rotary movement in a simple manner in the conveying direction 14 is transported.

Due to the rotary movement of the drum 2 align at the same time elongated solid parts 16 in the conveying direction 14, so that they are approximately parallel to the spiral axis 12 in the interior 11th the spiral 10 are guided. This will surely avoid that the elongated solid parts 16 perpendicular to the spiral axis 12 get into the spiral 10 and through the spiral 10 fail. Due to the spiral 10, only the fine solid F fall through it in a first collection container 18 collected and transported if necessary. The coarse solid G is passed through the spiral 10. At the end of the spiral 10, it falls into a second collecting container 20 and will also be removed if necessary. Instead of the collecting containers 18, 20, conveying devices, such as conveyor belts or screw conveyors be to continuously remove the solid F, G.

Figure 2 shows a schematic section through a curved Spiral 10. This is the main principle of operation of the curved spiral 10 explained. The spiral axis 12 (and with it the entire spiral 10) points according to Figure 2 shows a curvature. Because of the curvature is the top one Distance o between two successive turns larger than the lower distance u between two turns. On Solid part R can only be in the lower part of the spiral 10 clamp where the distance u between two turns is small. A clamped solid part P is through the Rotational movement of the spiral 10 promoted upward, and at the same time the distance between the turns becomes larger, so that the Solid part P loosens and falls.

The same applies in a similar way to wire pieces 24 or the like Solid parts that are hook-shaped and hang over the rod 8 with the hook opening. At a such wire pieces would only move in one plane 24 usually lead to constipation. In the present Fall, the piece of wire 24 is rotated together with the spiral 10 upwards. Especially at the top The turning point of the spiral 10 is the hook opening after directed upwards so that the wire piece 24 can fall down. This advantageous mechanism of the spiral 10 is independent whether there is a curvature of the spiral 10.

According to Figure 3, the smoldering drum 26 of a pyrolysis plant via a feed shaft 27 and a feed device 28 loaded with waste A. The waste A is in the smoldering drum 26 at around 450 ° C. This creates a Smoldering gas S and a solid or pyrolysis residue R. Die Smoldering drum 26 is preferred over not shown internal heating pipes heated. It is opposite the horizontal inclined and rotatable. On the feeder 28 opposite end of the smoldering drum 26, a discharge pipe 29 is arranged on the end the spiral 10 is attached. The discharge pipe 29 and the Spiral 10 form the sieve device 1. The discharge pipe 29 also serves as an alignment device for elongated Solid parts. With the spiral 10, the fine solids F separated from the coarse solids content G.

The discharge pipe 29 with a connected spiral 10 opens into a discharge device 30 which is opposite the rotating Smoldering drum 26 sealed gas-tight via mechanical seals 32 is. The same as the discharge device 30 the feed device 28 to the smoldering drum 26 via mechanical seals 32 sealed gas-tight. This is to be avoided be that atmospheric oxygen penetrates into the smoldering drum 26 and the one that runs largely oxygen-free in the smoldering drum 26 Pyrolysis process affected. In addition to the pyrolysis residue R arises in the carbonization drum 26, the carbonization gas S, which via the discharge pipe 29 into the discharge device 30 flows and from there via a carbonization gas outlet 34 is derived.

To the spiral 10 arranged in the discharge device 30 can be dashed in an alternative embodiment in Figure 3 Connect shown tube 37 through which the coarse solid G discharged from the discharge device 30 becomes. The spiral 10 is in this case between the discharge pipe 29 and the tube 37 arranged.

With the arrangement of the spiral 10 on the discharge tube 29 Smoldering drum 26 is the pyrolysis residue R immediately after the smoldering drum 26 into a fine solid fraction F and a coarse solid content G separated. The danger of one Blockage from the smoldering drum 26 downstream components is therefore only minor.

The screening device is generally suitable for direct connection on rotating pipes, e.g. Rotary kilns or smoldering drums, in which the solid is subjected to treatment what it should be separated after.

The fine residual material F separated with the screening device 1 is preferably a so-called for further processing Subjected to wind sifting. The light ones, in particular carbonaceous, solids from the heavy Solid components separated. With such a wind sighting the solid is fed to an air stream so that the light solids are entrained with the air flow. A zigzag-shaped one has proven particularly useful Exposed in the air from below and shaft the solid is fed from above or from the side.

FIG. 4 shows an alternative embodiment to the spiral 10 shown, in which a instead of the spiral 10 Number of rods 8 is arranged at the end of the drum 2. The rods 8 are each wound along a helix and can therefore be regarded as a multi-start spiral become. The individual rods 8 are at the end of each other Drum 2 preferably arranged rotatably offset by an angle of 30 °. Each individual rod 8 has an angle of rotation less than 360 °, does not form a complete rotation. In order to a particularly robust design is made possible. The decisive advantage with this multi-start helix, like also with the spiral 10 according to FIG. 1, there is the arrangement one or more helically wound rods 8, so that the rotary movement of the screening device 1 any stuck solid parts automatically to the end the screening device are transported further and dropped there become.

To support this self-cleaning mechanism the arrangement of a rod member 35 provided that largely parallel to the outer surface formed by the rods 8 runs. The rod member 35 is also in the embodiment arranged with the spiral 10, although there not shown in detail. It causes one on a pole 8 hanging solid part due to the relative movement between rod 8 and rod element 35 in conveying direction 14 is withdrawn from the rod 8. This is the direction of rotation the screening device 1 and the direction of rotation of the rods 8 on top of each other Voted.

In order to increase the stripping effect, the rod element 35 also wound and crossed along a helix the rods 8 preferably at an angle of 90 °. The slope of the rod element 35 preferably takes in the conveying direction 14 to increase the wiping effect. The effect will be further improved if several rod elements 35 are provided are. For example, these are approximately semicircular below the rods 8 arranged.

Another advantage of the arrangement of the rod element 35 can be seen in the fact that elongate solid parts 16, which are not aligned completely parallel to the longitudinal direction 3 in the drum 2, cannot fall through a gap between the rods 8. Because of the rotary movement of the drum 2, it may happen that the elongated solid parts 16 are also lifted up so that they meet the rods 8 at an acute angle at the outlet of the drum 2.
It can also be seen from FIG. 4 that a multi-start spiral 36 is arranged on the inlet side of the drum 2. In the exemplary embodiment, the multi-turn helix 36 comprises two helical sheets which are arranged so as to be rotationally offset from one another. Further sheets can also be provided. The coil 36 is arranged on the inside of the drum 2 and is designed in such a way that at least two coil sections overlap at each point on the drum base. In addition, the flanks of the helix, i.e. the sheets, are relatively high. This ensures that the solid R introduced by the feed device 6 is braked and does not fly through or shoot through the screening device 1 without the solid R undergoing screening.

The multi-pass sieve with several described for FIG Rods 8 can, without limitation, the spiral sieve 10 from FIG 3 replace.

A pyrolysis plant according to the invention with a screening device is characterized by a very simple and robust construction while ensuring trouble-free Operation without clogging. decisive Aspects for ensuring safe operation are the design of the screening device with the helical coiled rod 8 or with the rods 8 passing through the curvature of the spiral 10 caused differences in distance of the turns, the safe separation of elongated Solid parts due to the upstream alignment device as well as that by the rotational movement and spiral movement conditional automatic transport of solid R.

Claims (18)

1. Pyrolysis plant for refuse having a screening device (1) for solid residues (R), which is rotatable about its longitudinal axis (3) and into the interior of which the residues can be introduced, characterized in that the screening device (1) has a rod (8) which is wound along a helical line and a rod element (35) is provided, which is arranged fixedly with respect to the wound rod (8) and essentially parallel to the outer face formed by the wound rod (8).
2. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to Claim 1, characterized in that the rod (8) is designed as a spiral (10) with a plurality of turns, in particular with about 4 to 10 turns.
3. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to Claim 1 or 2, characterized in that a number of rods (8) are provided, the rod starts of which are arranged so as to be offset in terms of rotation.
4. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to Claim 3, characterized in that the rods (8) have an angle of rotation smaller than 360°, in particular smaller than or approximately equal to 180°.
5. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 4, characterized in that the rod element (35) is wound along a helical line in opposition to the rod (8), so that the said rod element forms, in particular, an angle of about 90° with the rod (8).
6. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 5, characterized in that a plurality of rod elements (35) are provided, the starts of which are arranged so as to be offset in terms of rotation.
7. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 6, characterized in that the rod (8) is fastened only at its rod start.
8. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 7, characterized in that the rod (8) is flexible.
9. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 2 to 8, characterized in that the spiral axis (12) of the spiral (10) is curved downwards.
10. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 9, characterized in that the rod (8) is metallic and, in particular, is a round iron bar or a tube.
11. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 10, characterized in that an aligning device is provided for the alignment of elongate solid fragments in the conveying direction (14), the said aligning device being arranged upstream of the rod (8) and opening into the interior (11).
12. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to Claim 11, characterized in that the aligning device is a drum (2) rotatable about its longitudinal axis (3).
13. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to Claim 12, characterized in that the rod (8) is fastened, in particular welded, to the drum (2) on the end face (4) located in the conveying direction (14).
14. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to Claim 12 or 13, characterized in that a coil (36), preferably a multi-flight coil (36), is arranged on the inside of the drum (2).
15. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to Claim 14, characterized in that the coil (36) is designed in such a way that it forms a closed circle, as seen in a top view in the direction of the longitudinal axis (3) of the drum (2).
16. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 15, characterized in that the screening device (1) is connected to a discharge side of a low-temperature carbonization drum (26) for the screening of pyrolysis residues obtained from the low-temperature carbonization drum (26).
17. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 16, characterized in that the distance between two turns of the spiral (10) or between two rods (8) is about 100 to 300 mm, in particular 180 mm.
18. Pyrolysis plant for refuse having a screening device (1) for solid residues (R) according to one of Claims 1 to 17, characterized in that the interior (11) formed by the rod (8) has a diameter of about 1.5 m and a length of about 0.5 to 1.5 m.

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