WO1993013862A1

WO1993013862A1 - Wash-out tub for residual concrete

Info

Publication number: WO1993013862A1
Application number: PCT/DE1992/000022
Authority: WO
Inventors: Horst Brenner
Original assignee: Horst Brenner
Priority date: 1991-01-09
Filing date: 1992-01-16
Publication date: 1993-07-22
Also published as: DE4143029A1; DE4143029C2

Abstract

A wash-out tub (10) as a device for reprocessing residual concrete has a first travelling conveyor (16) conveying in a direction (20) from the front to the rear region of the tub, a second travelling conveyor (30) in the rear region of the tub, a transverse partition (24) in the region between the first and second conveyors (16, 30) and conveying means leading out of the tub in the rear region to extract the cleaned gravel and sand components of the residual concrete. This wash-out tub is characterised in that the partition (24) of the tub (12) is permeable by gravel and sand components and for other granular components of the residual concrete, the first conveyor is supported on said partition and the conveying means takes the form of a worm conveyor with a shaft having spiral blades arranged to rotate and be driven and in that the shaft of said worm conveyor is supported outside the reception region for the material conveyed.

Description

DESCRIPTION

Wash-out trough for residual concrete

TECHNICAL AREA

The invention relates to a wash-out trough as a device for reprocessing residual concrete.

A reprocessing of unused residual concrete quantities in concrete processing or transporting companies is becoming increasingly necessary for reasons of environmental protection. In addition, reprocessing also has economic advantages, since the components obtained as residual concrete can be reused in the production of new concrete.

STATE OF THE ART

From DE-OS 2929 857 a device for reprocessing residual concrete is known, in which a wash-out trough is used. The trough, which is semicircular in its lower area, is divided by a transverse wall into a first, larger prewash chamber and a second, smaller post-wash cart. The residual concrete is introduced into the first chamber and transported by means of a screw conveyor in the direction of the transverse wall, whereby the concrete is freed of the cement components adhering to it. By means of a first bucket wheel arranged next to the transverse partition, the components of the residual concrete that accumulate in front of the transverse wall, or the components transported there by the transport screw, are conveyed onto a slide. From this slide, the gravel and sand components then pass over the transverse wall into the second post-washing chamber behind the transverse wall. The gravel and sand components are then removed from the post-washing chamber using a second bucket wheel a slide and then conveyed out of the washout trough via this slide. Contrary to the conveying direction of the residual concrete within the wash-out trough, fresh water is passed through the trough. This fresh water is introduced into the post-washing chamber and flows from there via an overflow into the pre-washing chamber. In the area of the residual concrete inlet opening, the water flows out of the washout trough via an overflow. The conveyor screw present in the prewash chamber consists of two end walls, between which axially parallel, longitudinal struts forming a cylinder jacket extend. The longitudinal struts serve as carriers for the conveyor screw.

These end walls are required for reasons of stability, since the blades of the screw conveyor cannot cantilever freely for reasons of stability; the load on the screw conveyor during transport of the residual concrete through the trough is so great that a stable mounting of the screw conveyor cannot be dispensed with even in the end region thereof.

Another washout trough of the type mentioned at the outset has become known from utility model 8904400, in which two chambers are also hermetically separated from one another by a transverse wall. The transport screw present in this trough is stabilized at both ends by a star-like end wall. These two star-like walls are relatively filigree and thus material-saving. In order to discharge the cleaned gravel and sand components of the residual concrete, a screw conveyor leading out of the trough in the direction increasing to the horizontal is provided. The remaining constituents of the concrete are fed into the cup of a cup wheel. Although the conveyed the screw conveyor is ^"fed in already purified state, yet the bearing of the screw conveyor is an unsatisfactorily short life Lebens¬ been detected. This is probably due to the fact that water and dirt particles can penetrate into the bearing area and thereby prevent the bearings from permanently functioning properly. In order to counteract this, the bearing units could be sealed in such a way that they are protected against the ingress of water and dirt by means of complex constructive measures. However, this would mean that the economic use of such screw conveyors would no longer be justifiable and thus other solution options for discharging the bulk material would be preferred.

Another known reprocessing device is in the form of a wash-out screw. The residual concrete to be washed out or cleaned is moved along a screw conveyor, which is aligned with its axis of rotation obliquely upwards against the horizontal. In the area of the inlet opening of this screw conveyor there is a relatively large inlet funnel which is completely filled with water, so that in this area the screw conveyor is always completely immersed in the water. Since the water in this area is both very heavily polluted and very aggressive due to the residual concrete, this leads to major problems for the bearing of this screw conveyor. Despite complex sealing measures, this bearing is subject to heavy wear. As a result, the life of this bearing is undesirably short.

The known screw conveyors mostly have a conveyor trough made of sheet metal. This conveying trough is spaced from the outer contour of the threaded blades in such a way that this distance is in any case greater than the largest diameter of the grain fraction of the prepared concrete. This is to prevent additives from wedging between the wall of the conveyor trough and the threaded blades during the conveying process, which can lead to damage to the conveyor trough and the threaded blades. This measure reduces the funding performance of the screw conveyor. Furthermore, an exchange of the conveyor trough or its repair is only possible with great effort.

PRESENTATION OF THE INVENTION

On the basis of this prior art, the object of the invention is to provide a wash-out trough of the type mentioned at the beginning which enables residual concrete to be reprocessed as economically as possible.

This invention is given by the features of claim 1. The washing trough known from the prior art is accordingly characterized in that the transverse partition arranged in it for separating the pre-washing chamber from the post-washing chamber is designed to be permeable to gravel and sand components as well as other granular components of the residual concrete, and in that the latter Cross partition the conveyor arranged in the prewash chamber, such as. B. the screw conveyor is stored. The permeability of the transverse partition wall can in particular be produced simply by leaving a gap between the transverse partition wall and the inside of the trough wall. This measure is based on the knowledge that a hermetic separation of the prewash chamber from the postwash chamber is not necessary. Due to the beaker wheels available in the prior art and the direction of flow of the fresh water from the post-washing chamber into the pre-washing chamber, a certain mixing of the amounts of water present there cannot be avoided in both chambers. Then the transverse wall can be permeable not only for the water but also for the residual concrete components d. H. be formed for the gravel and sand components.

The invention is also characterized in that the shaft of the discharge screw leading out of the trough half of the receiving area for the material to be conveyed is stored. As a result of this further measure, the bearings of the shaft do not come into contact with the material to be conveyed and the existing dirty water. In this respect, the aggressive cleaning water due to the high pH value of the residual concrete, which is present despite the diluting effect of the amount of water used, cannot have any harmful influence on the storage units. Furthermore, existing dirt constituents or sand and gravel fractions cannot get into the area of the storage units and limit their functionality. By positioning the shaft outside the receiving area for the material to be conveyed, a screw conveyor is thus made available which ensures a high degree of maintenance-free operation and at the same time high functionality.

The permeability is made possible in the washout trough according to the invention, for example, by the fact that there is a free space between the transverse partition and the trough wall. Through this free space, the gravel and sand components can be transported "through" the cross-partition from the pre-wash chamber into the post-wash chamber through the conveyor screw or, more generally, through the conveyor device present in the first pre-wash chamber. At the same time, the screw conveyor can be mounted directly on the transverse partition, so that there is no need for a separate end wall for the screw conveyor; the transverse partition not only forms a certain separation of the pre-wash chamber from the post-wash chamber, but at the same time also a support for the front ends of the screw conveyor. A wash-out trough designed in this way allows very considerable savings in material, without the quality of the wash-out process being adversely affected thereby.

If the wash-out trough according to the invention is formed in its prewash chamber with the transport screw known from the prior art, the transverse partition can be on the Axis of rotation of this screw conveyor are stored. It is possible to make the transverse partition wall rotatable together with the screw conveyor about the axis of rotation of the screw conveyor. In this case, the screw conveyor can be firmly attached to the cross partition. If the cross partition is not designed to be rotating, the end of the transport screw could be movably mounted on the cross partition.

According to another development of the invention, the axis of rotation of the conveying device present in the post-washing chamber, with which the cleaned gravel and sand components are transported out of the trough, coincides with the axis of rotation of the conveying device present in the pre-washing chamber, e.g. B. the screw conveyor together.

In the known washing troughs, the process of filling the residual concrete into the washing trough proves to be a problem. If the residual concrete is poured more or less suddenly into the washing trough, a great deal of water is displaced for a short time, which flows out of the prewash chamber with a more or less high bow wave both into the postwash chamber and via the overflow from the washing trough. In this way, a strong mixing of the water quantities present in the post-washing chamber and the pre-washing chamber is brought about. In addition, there is an undesirably large loss of water. In order to contain this flood wave and to prevent the residual concrete from suddenly spreading over the entire area of the prewash chamber and thus reaching the postwash chamber too quickly, the area between the filling opening for the residual concrete and that between the prewash chamber and the After-wash chamber arranged transverse partition, a further transverse partition can be arranged within the wash-out trough. This second transverse partition, which can be arranged to be adjustable in the longitudinal direction, that is to say in the conveying direction of the wash-out trough, can be wash chamber existing conveyor such. B. be connected to the existing screw conveyor so that this transverse partition and the conveyor can rotate together about the same axis of rotation. This second transverse partition also has a permeability for the residual concrete in the direction of transport. This can in turn be achieved in that this transverse partition also maintains a certain distance from the inside of the trough wall. Due to the gap formed between the transverse partition and the trough wall, for example, the residual concrete or its components can be transported by means of the screw conveyor along the inside of the trough wall in the direction of the prewashing chamber.

This transverse dividing wall in the area of the filling opening also proves to be an extremely useful additional device in the washout troughs known from the prior art.

In a structurally simple embodiment of the conveyor screw according to the invention in combinatorial fashion, the shaft is designed as a hollow profile, a stationary bearing element being present within the shaft and at least one rotary bearing device being arranged between the bearing element and the inner wall of the shaft. The bearing element is connected in the receiving area of the screw conveyor to the wall of a support device surrounding the screw conveyor. The bearing element is preferably formed as a round profile, the rotary bearing device itself being designed as a ball bearing unit, in such a way that the rotation of the shaft around the stationary bearing element can be optimally designed without great friction losses and with regard to freedom from maintenance.

To stabilize the shaft during the rotary movement, there are two rotary bearing devices which are arranged at a distance from one another in the longitudinal direction of the shaft. This can cause the rotating shaft to tilt under certain circumstances compared to the bearing unit, which could have an unfavorable effect on the wear occurring during the rotary movement.

In a preferred development of the conveyor screw according to the invention, the conveyor screw has a conveyor trough which is designed as a flexible, elastic track. This measure ensures a certain flexibility of the conveyor trough during the conveying process. Therefore, the material to be conveyed cannot jam between the threaded blades of the shaft and the conveyor trough during the conveying process. Preference is given to using highly wear-resistant plastic as the material for the conveyor trough, the material polyurethane being used in particular, with a Shore hardness of 70-90 degrees. The result is less wear and a longer service life.

In order to ensure optimal conveying performance, the conveyor trough lies at least in some areas on the outer contour of the threaded insert. As a result of the elastic flexibility of the conveyor trough, the material to be conveyed cannot wedge between the threaded blades of the shaft and the conveyor trough itself. In addition, the flexible elastic conveyor trough can be easily replaced if damaged, which in the known, made of sheet metal

Conveyor channels is not possible or only with great effort. The easy interchangeability of the flexible elastic conveyor trough is made possible by the fact that the conveyor trough is clamped between two channel profiles surrounding the screw conveyor. By loosening the clamping connection, which is implemented constructively, for example, by means of a continuously arranged screw connection, the flexible, elastic conveyor trough can be exchanged without major problems.

The above features of the screw conveyor can be can be combined in any way as far as they are not obviously mutually exclusive.

Further features and advantages of the invention are specified in the subclaims and in the exemplary embodiment below.

BRIEF DESCRIPTION OF THE DRAWING

The invention is described and explained in more detail below on the basis of an exemplary embodiment. Show it:

1 is a schematic, perspective view of the interior of a washout trough according to the invention,

2 shows a schematic perspective illustration of one of the conveyor screws according to the invention belonging to another washout trough according to the invention,

3 shows a schematic longitudinal section through the screw conveyor according to the invention according to FIGS. 2 and

FIG. 4 shows a schematic cross section through the conveyor screw according to the invention according to FIG. 2.

WAYS OF CARRYING OUT THE INVENTION

A washing trough 10 used for reprocessing residual concrete has a trough 12 with a trough wall 13 which is semicircular in its lower cross-sectional area. In the area of its front end there is a filling opening 14 in the washing trough 10, through which residual concrete can be introduced into the trough 10.

A transport screw 16 is present in the washout trough 10. the, whose longitudinal axis 18 is aligned parallel to the longitudinal extent of the trough 10. During the rotary movement of the screw conveyor 16, residual concrete present in the washing trough is moved further in the transport direction 20 along the wall 13 of the trough.

At its front and rear end, the transport screw 16 ends in a front cross partition 22 and in a rear cross partition 24. The front cross partition 22 lies more or less directly on the front end wall, which is not shown in the drawing, of the washout trough 10 on. The rear transverse partition 24 is at a distance from the trough wall 13, so that there is a gap 26 between the trough wall 13 and the transverse partition 24 in its area. In this gap 26, the gravel and sand components of the residual concrete - in the drawing from right to left - can be transported "through" the transverse partition 24.

The area between the two transverse partition walls 22, 24 is referred to as the prewash chamber 27.

A so-called post-wash chamber 28 is present within the wash-out trough 10 on the other side of the transverse partition 24 to the pre-wash chamber 27. Fresh water flows from the outside into this post-washing chamber 28, which flows through the gap 26 into the post-washing chamber 28 and then flows out of the washing-out trough 10 in the region of the front transverse partition 22.

In the area of the post-washing chamber 28 there is a cup wheel 30, the cups 32 of which take up the gravel and sand components present in the area of the trough wall 12 and drop them onto a discharge device which will be described in more detail below. About this discharge device, which is a screw conveyor 37 (Fig. 2, 3, 4), the in the area Post-wash chamber 28 removes gravel and sand components that are obtained in a cleaned manner from the wash-out trough 10. The cups 32 can be supported on the rear transverse partition 24.

Another transverse partition 34 is present between the front transverse partition 22 and the rear transverse partition 24. This transverse partition 34 is designed in the same way as the rear transverse partition 24. It too is at a distance from the trough wall 12, so that a gap 26 is also present in the area of this transverse partition wall 34, through the residual concrete or its gravel and sand components along the trough wall 12 in the transport direction 20 "through" this cross partition wall 34 can be conveyed through. The transverse partition 34 can be adjusted in the transport direction 20. This makes it possible to design the immediate filling area for the residual concrete within the washout trough 10 to be of different sizes. In the event of very large quantities of residual concrete occurring in the short term, the transverse partition wall 34 will be positioned more towards the rear transverse partition wall 24, while in the opposite case, if relatively small quantities of residual concrete are produced per unit of time, the transverse partition wall 34 will be oriented more towards the front transverse partition wall 22 becomes.

While the front and rear transverse dividing walls 22, 24 serve as end supports for the respective ends of the transport screw 16, the further transverse dividing wall 34 arranged in between is fastened to the longitudinal struts 38, which parallel to the transport direction 20 the turns of the transport - Connect screw 16 together and thus serve to stabilize the screw conveyor 16. All transverse partition walls 22, 24, 34 rotate together with the screw conveyor 16 about a common shaft, the axis of which coincides with the longitudinal axis 18.

A transport screw 16 designed in this way has one extremely low use of material, without there being any noticeable loss in efficiency.

The washout trough 12.1 shown schematically in FIGS. 2, 3 and 4 essentially differs from the latter by its cup 32.1 present in the rear region. In contrast to the pot-like cups 32 of the trough 12, these consist of side-by-side, arch-shaped scooping cups 32.1.

In addition, the trough 12.1 - in the same way as the trough 12 (FIG. 1) - is filled with water to approximately just below the height of its longitudinal axis 18 such that the axis 18 does not come into contact with the filled water. During the rotation of the screw conveyor 16, the gravel and sand components present in the residual concrete are washed out. In the rear area 40 fresh water is continuously fed into the trough 12.1, which leaves the same again from its front area 42. The suspended components and the cement are continuously washed out with the water leaving the trough 12.1. From the screw conveyor 16, the gravel and sand components that are cleaned in the bottom region of the trough 12.1 due to their gravity are conveyed in the direction 20 to the rear region 40.

The screw conveyor 37 protrudes into the end of the washing chamber 28 in the rear area 40 of the trough 12.1. The screw body 44 of the screw conveyor 37 is surrounded by a housing which has an upper profile part 46 and a lower profile part 48. The axis of rotation 40 of this screw body 44 includes an angle of inclination 49 of approximately 45 ° with the longitudinal axis 18.

In the upper area of the screw conveyor 37, the lower profile part 48 is formed in a downward-opening slide 50. In the longitudinal direction of the axis 52 on the upper head of the The worm body 44, above the slide 50, the drive motor 54 for the worm body 44 is placed. The lower end of the screw conveyor 37 ends with its screw body 44 above the longitudinal axis 18, which is also the axis of rotation for

05 is the cup wheel 30.1 present in the rear area 40. The lower end of the screw conveyor 37, which at the same time forms a receiving area 56 for the material to be conveyed, is placed in the rear area 40 in such a way that the cups 32.1 of the cup wheel 30.1 that are present in this trough area

Pour 10 gravel and sand components from above into the lower profile part of the screw conveyor 37 forming a tub-like housing. The water also filled into the lower profile part 48 of the screw conveyor 37 can flow through openings in this lower profile part 48

15 flow back the trough 12.1. The maximum water level within the receiving area 56 is indicated at 51. The gravel and sand constituents are thus led obliquely upwards out of the washing trough 10.1 from the screw body 44.

20th

The screw body 44 of the screw conveyor 37 has a rotatable hollow shaft 58, on the outside of which threaded blades 60 are arranged. In the lower region 56 of the screw conveyor 37 there is a rod-shaped bearing element within the shaft 58

25 62 arranged in the direction of the longitudinal axis 52, which is fastened to a lower end wall 64, which is connected at the end face to the lower profile 48. At the free end of the bearing element 62 and approximately in the third point of the bearing element 62 there is between the bearing element 62 and the inner wall

30 rotary shaft 58 a ball bearing unit 66 is arranged.

The upper profile part 46 and the lower profile part 48, both of which have an approximately U-shaped cross section, each have an outwardly projecting edge 68 at their free end. Between the two edges 68 of the upper profile 46 and the lower profile 48 is a flexible one Plastic sheet 70 inserted. The upper profile part, the lower profile part and the plastic web 70 are connected by means of a screw 72. The flexible plastic web 70 is designed as a conveyor trough and lies directly against the outer contour of the threaded blades 60 in such a way that contact between threaded blades 60 and the flexible plastic web 70 is present approximately on the length of half the circumference of the threaded blades 60.

Claims

EXPECTATIONS

01) wash-out trough (10) as a device for reprocessing residual concrete, with - a trough (12) which has a semicircular interior cross section in its lower region,

a revolving first conveying device (16), the conveying direction (20) of which is directed from the front to the rear trough area, a water inlet opening in the rear trough area,

- a water drainage opening in the front trough area,

a filling opening (14) for the residual concrete in the front trough area,

a revolving second conveyor device (30) in the rear trough area, the axis of rotation of which coincides with the axis of rotation of the first conveyor device (16),

- a transverse partition (24) in the area between the first and second conveyor devices (16, 30),

- A conveying means leading out of the trough (12) in the rear trough area for the discharge of the cleaned gravel and sand components of the residual concrete, that is, the fact that

- The transverse partition (24) of the trough (12) is permeable for gravel and sand components and for other granular components of the residual concrete,

the first conveyor is mounted on this transverse partition,

the conveying means is designed as a screw conveyor (37) with a drivable, rotatably mounted shaft (58) with threaded blades (60),

- The shaft (58) of this screw conveyor (37) is mounted outside the receiving area (56) for the material to be conveyed. 02) wash-out trough according to claim 1, characterized in that a distance (26) is present between the transverse partition (24) and the inside of the trough wall (12),

03) wash-out trough according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t that

- The first conveyor is in the form of a transport screw (16), - The axis of rotation (18) of this transport screw (16) in

Is the center of the circle of the semicircular lower region of the trough (10),

- The transverse partition (24) is mounted on this axis of rotation (18).

04) Wash-out trough according to claim 3, so that the transverse partition (24) is fastened to the conveyor screw (16) so that the transverse partition (24) and the conveyor screw (16) can be rotated together about the axis of rotation of the conveyor screw.

05) Wash-out trough according to one of the preceding claims, such that the axis of rotation of the second conveyor (30) coincides with the axis of rotation of the first conveyor (16).

06) Wash-out trough according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that

- A second transverse partition (34) is present, which is arranged in the region of the first conveyor (16), and

- There is a distance (26) between the second transverse partition (34) and the inside of the trough wall (12). 07) Wash-out trough according to claim 6, characterized in that the second transverse partition (34) is arranged in the region between the filling opening (14) for residual concrete and the first transverse partition (24).

08) wash-out trough according to claim 6 or 7, characterized in that the second transverse partition (34) is connected to the first conveyor (16) so that this transverse partition (34) and the conveyor (16) together about the axis of rotation of the first conveyor (16) are rotatable.

09) Wash-out trough according to claim 6, that the second transverse partition (34) in the longitudinal direction of the trough, d. H. is arranged to be adjustable in the conveying direction (20) of the first conveying device (16).

10) Wash-out trough according to claim 1, so that the second conveyor (30) is fastened to the first transverse partition.

11) Wash-out trough according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that

- The shaft is designed as a hollow profile (58),

a stationary bearing element (62) is present within the shaft (58),

- At least one rotary bearing device (66) is arranged between the bearing element (62) and the inner wall of the shaft (58). 12) Wash-out trough according to claim 11, characterized in that the pivot bearing device is formed as a ball bearing unit (66).

13) Wash-out trough according to claim 11, so that two rotary bearing devices (66) are provided which are arranged at a distance from one another in the longitudinal direction of the shaft (58).

14) Wash-out trough according to claim 11, so that the conveyor screw (37) has a conveyor trough which is designed as a flexible, elastic track (70).

15) Wash-out trough according to claim 14, so that the web (70) consists of highly wear-resistant plastic, in particular polyurethane.

16) Wash-out trough according to claim 15, so that the polyurethane has a Shore hardness of 70 to 90 degrees.

17) Wash-out trough according to claim 11, so that the web (70) bears at least in regions on the outer contour of the threaded insert (60).