DE202006000559U1 - Agitator for waste treatment plant has agitating arms provided with rod shaped, bar like or rib like wear protection elements between and beside circumferential surface of agitator shaft - Google Patents

Abstract

The agitator has agitating arms (6) which are provided with rod shaped, bar like or rib like wear protection elements between and beside circumferential surface of the agitator shaft (5). The wear protection elements are again removable from the surface of the free circumferential surface.

Description

The Invention relates to a stirrer, in particular a waste treatment plant, that in a treatment chamber for arranged at least partially corrosive and / or abrasive material is and in which on a rotating driven agitator shaft arranged in the circumferential direction and / or axially distributed a plurality of radial stirring arms are.

Especially at waste treatment plants are the treatment chambers and their agitators usually large volume built to be over great Capacity and throughput capacity feature. In so-called percolation chambers, which are also equipped with such agitators be equipped, is the material to be treated from above a leaching supplied around soluble Separate substances from the rest of the material. The agitators can be included in diameter with agitator arms of several meters and require in quantities of several Pass through tons of waste material in the treatment chamber and to be able to prepare mixing a stable construction. The in such treatment chambers or percolation chambers treated mixed waste are ordinary interspersed with components, the strong wear effects on the agitator parts exercise. It can the signs of wear have both abrasive and corrosive causes. Therefore subject the agitator parts, as far as they are in contact with abrasive and / or corrosive components come, even an elevated one Wear.

Around the agitator arms to move through the at least partially compact material, and To split and loosen this are for driving the agitator shaft high torques required. Because of these high torques it also required the agitator arms on the agitator shaft one in the circumferential direction as possible wide footprint to give and the agitator arms to be provided with a high break-proof shape.

In WO 95/20554 discloses a composting plant in which in a composting chamber over one in the conveying direction movable sieve plate several agitator shafts are arranged, the mixing and Aufloc tion of the treated Serve waste. These agitator shafts are in pairs one above the other lying horizontally and transversely to the sieve bottom and on its circumference respectively provided with paddle-shaped, radial projections, both a Mixing function as well as a conveying function exercise on the waste material. There are paddles provided in a specified embodiment, bent backwards in the direction of rotation are, as well as those which protrude radially straight from the shaft circumference. With both embodiments let yourself only a little mixing and To achieve a loosening effect. Especially in the embodiment with the straight paddles, the surface of the agitator shaft is the abrasive influences exposed to the waste material. Special precautions for avoidance the wear-intensive influences on the lateral surface the agitator shaft are not provided.

At another EP 0 876 311 B1 known apparatus for biological treatment, in particular for the composting of organic materials in a so-called. Reactor, a combined agitator or circulation plant is arranged, which provided with radial, paddle-like stirring arms agitator shaft extending in the longitudinal direction, ie in the direction of passage of the material. Again, no provisions are provided against the wear of the agitator shaft.

Incidentally, is for composting materials from pure green or biowaste the mechanical wear effect usually lower than household rubbish, the many hard and thus highly abrasive components, such as Sand, Stones, metal parts and the like, may contain and usually also contains.

Of the Invention is based on the object, a stirrer of the aforementioned Type with a stirring shaft to create their surface wear largely avoided or reduced to a minimum.

Is solved this object according to the invention by that the between and next to the stirring arms free peripheral surface the agitator shaft with a variety of patch, rod-shaped, strip-like or rib-like wear protection elements is provided.

Through these wear protection elements, the harmful, wear-causing effect of the abrasive and / or corrosive components of the treated, loosely located in the treatment chamber material on the peripheral surface of the agitator shaft during operation of the agitator weitge starting to be avoided by these wear-causing components of in the treatment chamber material are largely kept away from the surface of the agitator shaft. As far as these wear-intensive components are fine-grained and also usually wet or wet material, such as sand, mixed with other minerals, results in a particularly favorable effect, which is that in the course of operation between the wear protection elements on the Build up peripheral surface of the agitator shaft depositions and cover the peripheral surface largely or completely. It thus creates an additional highly effective wear protection for the peripheral surface.

If this additional Protective effect occurs, are only the radial outer surfaces of the Wear protection elements exposed to wear, so that these must be renewed from time to time. Not to the whole Agitator shaft, the have a weight of several tons and a length of more than 10 m can, need to expand, It is very advantageous to provide the embodiment according to claim 2. This allows a relatively simple replacement of the wear protection elements in the for this Purpose emptied treatment chamber.

Just in view of this interchangeability of wear protection elements the embodiments of claims 3 and 4 have proved to be particularly useful.

In Connection with the embodiment according to claim 4 carry the embodiments according to the claims 5, 6 and 7 also essential to the achievement of the aforementioned additional Wear protection at, by removing the deposits between the individual wear protection elements favor.

Of the Demand for high mechanical stability of the agitator shaft and in particular after a stable connection between the stirring arms and the agitator shaft Bear the embodiments according to claims 8 to 17 bill.

Based of the drawings, the invention is explained in more detail below. It shows:

1 in a schematically simplified isometric view half cut a percolation chamber with agitator and sieve bottom and underlying conveyor trough;

2 in an enlarged view a vertical section of in 1 illustrated percolation chamber with sieve bottom and conveyor trough;

3 an enlarged section III 2 ;

3a a single wear protection element on a peripheral portion of the agitator shaft;

4 a mixing arm as a cutout IV 2 ;

5 a side view V off 4 and

6 a view VI 4 ;

7 an isometric view of a section of the agitator shaft with two Rührarmen and some wear protection elements;

8th in cross section, the agitator shaft with a stirring arm;

8a and 8b the two lateral plate elements of the paddle 8th as individual parts;

9 a side view IX 8th ;

10 the two a mixing element forming a plate elements 8th as items and

11 on average, the arrangement of a wear protection element between the two Rührarmen the 7 ,

The in the 1 and 2 illustrated percolation chamber 1 is part of a treatment plant, for example, for residual household waste. In this percolation chamber 1 this is done from the top by an addition funnel 2 at the addition end of the percolation chamber 1 entered material, eg residual household waste, subjected to a percolation process. In this case, the material to be treated by spray nozzles 3 in the lid 4 the percolation chamber 1 are arranged distributed in the longitudinal direction, supplied washing liquid. In the percolation chamber 1 there is a stirrer shaft 5 extending over the entire length of the percolation chamber 1 extends. On the circumference of the agitator shaft 5 are several radial stirring arms 6 arranged. These cause a uniform mixing and loosening of the material in which the agitator shaft 5 is driven continuously or alternately in one or the other direction.

The motor drive for the rotation of the agitator shaft 5 is not shown in the drawing.

Below the agitator shaft 5 is as the lower end of the downwardly arcuately tapered percolation chamber 1 in a horizontal, longitudinally extending recess 7 a building ceiling 8th a sieve bottom 10 intended.

Below the sieve tray 10 there is a conveyor trough running parallel to it 11 with a conveyor spiral 12 , In this conveyor trough 11 be through the sieve bottom 10 falling or flowing fine-grained and liquid fraction fractions of the in the percolation chamber 1 through the rotating agitator shaft 5 collected and mixed material. The conveyor spiral 12 is driven so that they catch the Material in the direction of the arrow 13 in a transverse, at the end of the sieve 10 arranged conveyor trough 14 transported, in which also a conveyor spiral 15 located, which the recorded material in the direction of the arrow 16 transported on for further treatment.

The delivery side closes at the sieve bottom 10 a delivery shaft 17 by which in the percolation chamber 1 treated material gradually into a transverse to the sieve bottom 10 running conveyor trough 18 falls. In the conveyor trough 18 there is a conveyor spiral 19 that's above the sieve bottom 10 in the delivery shaft 17 carried material in the direction of the arrow 20 for further processing.

The total length LG ( 1 ) of the percolation chamber 1 is about 20 meters or more. Correspondingly long is the agitator shaft 5 , by means of only schematically shown, end bearing journals 21 . 22 in the area of the closed end faces of the percolation chamber 1 is rotatably mounted. Here are the journals 21 . 22 , in coaxial arrangement in each case on closed end walls 9 . 9 ' the agitator shaft 5 fixedly attached.

The agitator shaft 5 is designed as a hollow shaft and therefore consists of a hollow cylinder 1.5 whose steel jacket has a thickness d1 of about 40 mm ( 3 ). On the peripheral surface UF of the hollow cylinder 1.5 are in the circumferential direction and axially distributed a plurality of radial stirring arms 6 arranged. In the illustrated embodiment, six such in the circumferential direction in each case by 60 ° staggered stirring arms 6 visible, noticeable. Distributed to the total length LG are located on the agitator shaft 5 a total of seventeen stirring arms 6 , each having axial distances of about 1.3 m from each other.

That the stirring arms 6 evenly distributed in the circumferential direction on the agitator shaft 5 are arranged, has the advantage that during operation always at least one stirring arm 6 moved by the material to be treated and thereby larger torque fluctuations can be avoided.

These stirring arms 6 span a diameter D of about 4 m. The stirring arms 6 each consist of two intersecting plate elements 23 and 24 made of steel.

While the plane-parallel flat sides 25 and 26 of the plate element 23 each transverse to the axis 29 the agitator shaft 5 run, are the plate elements 24 arranged so that their plane-parallel flat sides 27 and 28 to the axis 29 take a parallel position (see 6 ). To increase the stability of these plate elements 23 and 24 each at the touching or crossing edges by multiple welds 30 rigidly connected.

In the embodiment of the 2 and 4 are the plate elements 23 with foot parts 31 provided, the curvature of the agitator shaft 5 or of the hollow cylinder 1.5 are fitted and extend over a circumferential length which corresponds to a central angle α of about 105 ° to 120 °, preferably 115 °. Thus, the foot part extends 31 a mixing arm 6 over more than a quarter of the total circumference of the agitator shaft 5 or of the hollow cylinder 1.5 , To ensure adequate stability, it should be on the circumference of the agitator shaft 6 seated foot part 31 extend over at least one fifth of the shaft circumference.

This foot part 31 is with its seated on the peripheral surface UF inner edge by welds 32 with the hollow cylinder 1.5 rigidly connected. As the 2 and 6 show, have the plate elements 23 a lean in front view, radially outwardly tapering triangular shape with concave arcuate side edges 33 and 34 ,

The plate elements 24 have, like 5 shows the surface shape of a radially outwardly tapering, isosceles, acute-angled triangle. Your just on the hollow cylinder 1.5 the agitator shaft 5 seated foot parts 33 are by double-sided welds rigid with the hollow shaft 1.5 connected. In this way, get the stirring arms 6 also a high bending stability in the axial direction.

The outer diameter d of the core of the agitator shaft 5 forming hollow cylinder 1.5 corresponds approximately to the radial length L of a Rührarms 6 (L = D / 2 - d / 2) or about half the diameter D, that of two diametrically opposed Rührarmen 6 is overstretched. In the illustrated embodiment, d = 0.9 L.

Due to this relatively large diameter d of the hollow cylinder 1.5 and by over a large peripheral portion α of over 90 ° (115 ° in the example) extending footboard 31 of the plate element 23 that is attached to the hollow cylinder 1.5 is welded, receives the paddle 6 the required stability and connection strength on the agitator shaft 5 in the direction of rotation or circumferential direction.

Conveniently, one of the two plate elements, preferably the slightly shorter plate element 23 , from two halves 23 ' and 23 '' that, as in 6 shown, mirror image on the flat sides 27 . 28 of the other plate element 24 arranged adjacent and welded to these.

It is obvious, instead of the plate element 23 the other plate element 24 to train as the longer and in two parts.

In the 7 to 11 is another, successfully tested in practice embodiment of the stirring arms shown. These stirring arms 6 ' each consist of two plate elements 60 and 61 that formed equal below and on the agitator shaft 5 are arranged mirror images of each other. The plate elements 60 and 61 each have a radial arm part 62 and a semicircular arcuate section 63 on which of the curvature of the peripheral surface UF of the agitator shaft 5 is adapted and applied to this. The radial arm parts 62 lie with their abutting flat sides in a common Axialebne 67 ' ,

How out 9 it can be seen have the radial arm parts 62 an outwardly tapered trapezoidal shape whose longitudinal edges 64 and 65 welded together.

In the circumferential direction are the arc sections 63 in each case over angular ranges β of at least 90 °, preferably 110 °, welded to the peripheral surface UF. Except for a small gap to keep as possible 66 ( 8th ) enclose the two arch parts 63 the peripheral surface OF of the agitator shaft 5 like a band almost completely.

Similar to the embodiment of the 4 to 6 , here are two in a radial plane 67 lying plate elements 68 and 69 provided, the center and right angles to the outsides 70 respectively. 71 the two arm parts 62 are welded. The radial plane 67 is at the same time the plane of symmetry of the plate elements 60 . 61 , Also these plate elements 68 . 69 are the same among themselves and each with foot parts 72 provided that the outer curvature of the arc sections 63 adapted and welded with these. These foot parts extend 72 each about angular sections δ of about 45 ° to 50 °. The outer edges 73 the plate elements 68 Here, too, concave arcuate to an outwardly tapering surface shape.

Because the agitator shaft 5 For reasons of statics has a large radius and thus also a large circumferential surface UF, which is in the rotational movement of the agitator shaft 5 moved by the at least partially abrasive, ie abrasion-causing material, it is subject to increased mechanical stress with respect to abrasion and wear. In order to protect against it, the between and beside the Rührarmen 6 free peripheral surface UF of the agitator shaft 5 with a variety of patch, rod-shaped, strip-like or rib-like wear protection elements 40 Mistake.

These wear protection elements 40 are again removable on the peripheral surface UF of the agitator shaft 5 appropriate. In principle, it would also be possible to wear protection elements 40 on the steel jacket of the hollow cylinder 1.5 For example, by means of screw fastened, which can be solved relatively easily again. Given the large number of such screw connections that would be required, it is less expensive and therefore more convenient to wear protection elements 40 firmly bonded to the steel jacket, preferably to be welded. In view of the fact that these wear protection elements 40 If they are worn out, replaced, ie need to be removed, it is beneficial if they, as in 3a shown only by a few short welds 41 welded in places.

Such welds 41 (short welds) can be separated relatively easily and quickly if necessary, eg with a disk grinder (Flex).

In any case, it is in such a possibility, the wear protection elements 40 from the agitator shaft 5 to remove, not required, the whole agitator shaft 5 expand and partially dismantle parts of the percolation chamber with various internals. Replacement and replacement of wear protection elements 40 can easily in the shut down and emptied treatment chamber 1 respectively.

The wear protection elements 40 preferably consist of rectangular profiled steel rods 40 ' ( 3a ), which are substantially axially, ie parallel to the axis 29 the agitator shaft 5 running at even circumferential intervals (a) on the peripheral surface UF of the agitator shaft 5 are arranged so that their longer profile edges 40 '' run radially.

The circumferential distances a of the wear protection elements 40 . 40 ' greater than the measured in the circumferential direction, about 20 mm to 25 mm amount profile width b of a wear protection element 40 . 40 ' , The circumferential distances a of the individual wear protection elements 40 . 40 ' correspond to four to six times, preferably five times, their profile width b, and their radial height h corresponds approximately to half their circumferential distance a. In the illustrated embodiment applies: a = 90 mm, b = 20 mm, h = 50 mm. There are a total of 36 wear protection elements in the embodiment 40 . 40 ' on the circumference UF of the agitator shaft 5 appropriate.

In the embodiment of the 7 to 11 are the wear protection elements 40 between the arch parts 63 the stirring arms 6 ' arranged and welded only with these. How out 11 it can be seen that are between two adjacent Rührarmen 6 ' arranged wear protection elements 40 each provided with a length which is the distance S of the arc sections 63 equivalent.

It is also easily possible, the length of the wear protection elements 40 to choose larger than the distance S and the ends of the wear protection elements 40 each on the outsides of the bow sections 63 to put.

With such an arrangement and such dimensions of wear protection elements 40 respectively. 40 ' are the optimal conditions given that the peripheral surface UF of the agitator shaft 5 is effectively protected against mechanical, abrasive and corrosive wear. A particular advantage, which is also achieved, is that, as in 3 shown, between the individual wear protection elements 40 . 40 ' the desired deposits 42 which in turn also provide protection against the corrosive media. By such deposits 42 , which gradually build up over time and can achieve high stability and density, forms over the entire peripheral surface UF of the agitator shaft 5 an effective, at least largely closed protective layer.

Claims (17)

Agitator, in particular for a waste treatment plant, which is located in a treatment chamber ( 1 ) is arranged for at least partially corrosive and / or abrasive material and in which on a rotationally driven agitator shaft ( 5 ) in the circumferential direction and / or axially distributed a plurality of radial stirring arms ( 6 ) are arranged, characterized in that the between and beside the Rührarmen ( 6 ) free peripheral surface (UF) of the agitator shaft ( 5 ) with a plurality of patch, rod-shaped, strip-like or rib-like wear protection elements ( 40 . 40 ' ) is provided. Agitator according to claim 1, characterized in that the wear protection elements ( 40 . 40 ' ) removable on the peripheral surface (UF) of the agitator shaft ( 5 ) are mounted. Agitator according to claim 1 or 2, characterized in that the agitator shaft ( 5 ) from a hollow cylinder ( 1.5 ) with a steel jacket on which the wear protection elements ( 40 . 40 ' ) are firmly bonded, in particular welded in places, are. Agitator according to claim 1, 2 or 3, characterized in that the wear protection elements ( 40 ) made of rectangular profiled steel rods ( 40 ' ) substantially axially extending at uniform circumferential intervals (a) on the peripheral surface (UF) of the agitator shaft ( 5 ) are arranged. Agitator according to one of claims 1 to 4, characterized in that the circumferential distances (a) of the wear protection elements ( 40 . 40 ' ) are larger than the profile width measured in the circumferential direction (b) of a wear protection element ( 40 . 40 ' ). Agitator according to claim 5, characterized in that the circumferential distances (a) of the individual wear protection elements ( 40 . 40 ' ) correspond to four to six times their profile width (b). Agitator according to claim 5 or 6, characterized in that the radial height (h) of the wear protection elements ( 40 . 40 ' ) approximately equal to half the circumferential distance (a). Agitator according to one of claims 1 to 7, characterized in that the diameter (d) of the agitator shaft ( 5 ) at least approximately the radial length (L) of a Rührarmes ( 6 ) corresponds. Agitator according to claim 8, characterized in that the stirring arms ( 6 ) each of plate elements ( 23 . 24 , respectively. 60 . 61 . 68 . 69 ) exist in two intersecting planes ( 67 . 67 ' ) are arranged, one of the two levels one in the axis ( 29 ) of the agitator shaft ( 5 ) lying axial plane ( 67 ' ) and the other plane is at right angles to the axis ( 29 ) of the agitator shaft ( 5 ) extending radial plane ( 67 ). Agitator according to claim 8 or 9, characterized in that the radial stirring arms ( 6 ) each have a first radially outwardly tapering plate member ( 23 ) whose flat sides ( 25 . 26 ) transverse to the axis ( 29 ) of the agitator shaft ( 5 ) and whose with an adapted curvature on the peripheral surface (UF) of the agitator shaft ( 5 ) seated and with this welded footboard ( 31 ) extends over at least one fifth of the shaft circumference. Agitator according to claim 9, characterized in that the radial stirring arms ( 6 ) in each case a second likewise radially outwardly tapering plate element ( 24 ) facing the first plate element ( 23 ) arranged crosswise at right angles and with a wider foot part ( 33 ) is welded to the peripheral surface (UF). Agitator according to claim 9, characterized in that one of the two plate elements ( 23 or 24 ) of two halves ( 23 ' . 23 '' respectively. 24 ' . 24 '' ), the mirror image of the flat sides ( 27 . 28 respectively. 25 . 26 ) of the other plate element ( 24 or 23 ) are arranged adjacent and welded to these. Agitator according to claim 9, characterized in that in an axial plane ( 67 ' ) lying plate elements ( 60 . 61 ) consist of two parts, each radially, radially outwardly tapered, flat side adjacent to each other welded arm parts ( 62 ) and that both parts with arcuate curved arc sections ( 63 ), which are mirror images of each other on the peripheral surface (UF) of the agitator shaft ( 5 ) and are welded to this. Agitator according to claim 13, characterized in that the arc sections ( 63 ) each at least approximately half the circumferential length of the agitator shaft ( 5 ) and at least over a quarter of the circumferential length or a central angle (β) of at least 90 ° with the peripheral surface (UF) are welded. Agitator according to claim 13 or 14, characterized in that the plate elements ( 68 . 69 ), which are transverse to the axis ( 29 ) of the agitator shaft ( 5 ) extending radial plane ( 67 ), each consisting of two parts, which are opposite, centrally on the outer flat sides of the flat side adjoining plate elements ( 60 . 61 respectively. 62 ) are arranged and welded to them and their on the arc sections ( 63 ) seated and welded to these foot parts ( 73 ) each extend over Zentriwinkel (δ) of at least 40 °. Agitator according to claim 15, characterized in that the plate elements ( 68 . 69 ), which are transverse to the axis ( 29 ) of the agitator shaft ( 5 ) extending radial plane ( 67 ), each having a radially outwardly tapering surface shape. Agitator according to claim 16, characterized in that the plate elements ( 68 . 69 ), which are transverse to the axis ( 29 ) of the agitator shaft ( 5 ) extending radial plane ( 67 ), in each case a concavely curved outer edge ( 73 ) exhibit.