DEVICE FOR DRYING SEWAGE SLUDGE

Abstract

A device for drying sewage sludge having a modular design composed of standard containers, the standard containers being disposed behind and optionally on top of one another. Slabs including heating lines are introduced on top of one another, in multiple levels, into the standard containers, serving as drying surfaces. Linear conveyors including deflections in a first and a last container distribute the sewage sludge across a width of the drying surfaces, turn and loosen the sewage sludge, and move this successively back and forth over the drying surfaces disposed on top of one another.

Claims

1. A device for drying sewage sludge, comprising at least one drying surface onto which the sewage sludge can be placed for drying, and comprising a linear conveyor, which comprises conveying elements that the linear conveyor moves in a longitudinal direction over the drying surface, wherein the device comprises modules, which are disposed behind one another in the longitudinal direction, the at least one drying surface continues through the modules, and the linear conveyor passes through the modules disposed behind one another.

2. The device according to claim 1, wherein the device comprises a plurality of drying surfaces which are disposed on top of one another and onto which the sewage sludge can be placed for drying, the device comprises a respective revolving linear conveyor for two drying surfaces disposed on top of one another, which comprises conveying elements that the linear conveyor moves in a longitudinal direction over the two drying surfaces disposed on top of one another and in opposite directions on the two drying surfaces, the device comprises modules, each of which comprises a plurality of drying surfaces disposed on top of one another, the modules are disposed behind one another in the longitudinal direction, the drying surfaces continue through the modules, the linear conveyor passes through the modules disposed behind one another, and the linear conveyor comprises a deflection in a first module and a deflection in a last module of the modules disposed behind one another.

3. The device according to claim 1, wherein the modules comprise standard containers.

4. The device according to claim 1, wherein the modules are disposed on top of one another.

5. The device according to claim 1, wherein the conveying elements take up a fraction of a width of the drying surfaces, and the conveying elements are distributed over the width of the drying surfaces.

6. The device according to claim 1, wherein the at least one drying surface comprises a heating device.

7. The device according to claim 1, wherein the at least one drying surface comprises heating lines or heating wires.

8. The device according to claim 7, wherein the at least one drying surface is subdivided in a modular manner in the longitudinal direction, and the heating lines are connected at the subdivisions of the at least one drying surface.

9. The device according to claim 1, wherein the at least one drying surfaces is detachably disposed in the modules.

10. The device according to claim 1, wherein the at least one drying surfaces comprises slabs, the upper sides of which form the at least one drying surface, and the slabs comprise a rust-proof reinforcement.

11. The device according to claim 1, wherein the at least one drying surface comprises slabs, the upper sides of which form the at least one drying surfaces, and the slabs comprise a binding girder.

12. The device according to claim 1, wherein the at least one drying surface is fluid-tight.

13. The device according to claim 1, wherein the first module comprises a loading point and/or a discharge point for the sewage sludge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The invention will be described hereafter in greater detail based on one exemplary embodiment shown in the drawings. In the drawings:

[0024] FIG. 1 shows a device according to the invention in a side view;

[0025] FIG. 2 shows a side view of a module of the device from FIG. 1; and

[0026] FIG. 3 shows a front view of a module of the device from FIG. 1.

[0027] The drawings are simplified schematic illustrations to provide an understanding of the invention and to describe the same.

DETAILED DESCRIPTION OF THE INVENTION

[0028] The device 1 according to the invention shown in the drawings for drying sewage sludge has a modular design and comprises standardized, so-called ISO containers 2, serving as modules 3, which are disposed behind one another in a longitudinal direction L. Containers 2 or modules 3 can also be disposed on top of one another in the form of levels, whereby a length of the device 1 is shortened. In the exemplary embodiment, two containers 2 at a time are placed on top of one another. Bottom containers 2 are placed onto strip foundations 4, for example.

[0029] The containers 2 forming the modules 3 comprise standardized container corners 5, at which the containers 2, which are disposed behind and on top of one another, are mutually connected.

[0030] In addition, the containers 2 comprise (longitudinal) side walls 6, a floor 7 and a ceiling 8, which is to say the containers 2 disposed behind one another have the shape of a rectangular tube. A first container 9 and a last container 10 of the containers 2 disposed behind one another comprise an end wall 11. Side walls 6 facing an observer are not shown in FIGS. 1 and 2, so that installations in the containers 2 or modules 3 of the device 1 are visible.

[0031] One or more slabs 12 are disposed in each container 2. If only one slab 12 is disposed in a container 2, this may be disposed horizontally, which is to say parallel to the floor 7 and the ceiling 8 of the container 2, or obliquely in the container 2. If multiple slabs 12 are disposed in a container 2, the slabs 12 are disposed horizontally, which is to say parallel to the floor 7 and the ceiling 8 of the container 2, in the container 2. Upper sides of the slabs 12 form the drying surfaces 13. Multiple slabs 12 are disposed behind one another in the longitudinal direction L in each container 2, and intermediate spaces between the slabs 12 are bridged by metal sheets 14, so that the drying surfaces 13 extend continuously through all of the containers 2 disposed behind one another.

[0032] One to four slabs 12 are disposed on top of one another in each of the containers 2 forming the modules 3 of the device 1 according to the invention, so that the device 1 on each level comprises four drying surfaces 13 on top of one another. If the device 1, as a result of containers 2 being disposed on top of one another, comprises multiple levels, the number of drying surfaces 13 increases accordingly. Containers comprising two, six, eight or more drying surfaces 13 disposed on top of one another are also possible. While the invention does not preclude an odd number of drying surfaces 13 disposed on top of one another, an even number of drying surfaces 13 disposed on top of one another is preferred, so that the sewage sludge can always be conveyed back and forth.

[0033] The device 1 according to the invention comprises a respective linear conveyor 15 for two or more of the drying surfaces 13 disposed on top of one another, which at one end distributes sewage sludge that has been placed onto an upper drying surface 13 across a width B of the drying surface 13, loosens and turns the sewage sludge, and conveys this to the other end of the drying surface 13. At the other end of the upper drying surfaces 13, the sewage sludge drops onto a drying surface 13 disposed therebeneath, where the same linear conveyor 15 again loosens, turns and conveys the sewage sludge back to the one end of the drying surface 13. There, the sewage sludge again drops onto a drying surface 13 disposed therebeneath, on which the sewage sludge is conveyed by another linear conveyor 13 back to the other end and, on a further drying surface 13 disposed therebeneath, back to the one end. At the end of a lowermost drying surface 13, the sewage sludge is removed from the device 1 in the dry state. A linear conveyor 15 that only conveys the sewage sludge over one drying surface 13, or over more than two drying surfaces 13, is also conceivable.

[0034] In the exemplary embodiment, the linear conveyors 15 are continuous-flow conveyors comprising cross beams 16 that extend transversely across the width B of the containers 2 and the drying surfaces 13 and are displaceably guided on horizontal rails 17 in the longitudinal direction L. In the exemplary embodiment, the rails 17 are L profiles, which are attached to the insides of the side walls 6 of the containers 2, parallel to and above the drying surface 13. The cross beams 16 can glide on the rails 17 or roll by way of rollers, for example. Multiple cross beams 16 are attached to the traction means 18, uniformly or non-uniformly distributed over the longitudinal direction L.

[0035] The cross beams 16 are pulled by cables or chains, serving as traction means 18, in the longitudinal direction L over the drying surface 13. A traction means 18 in a center of the cross beams 16 is conceivable, as are multiple traction means 18 distributed over the width B. In the exemplary embodiment, the linear conveyor 15 comprises two traction means 18 on inner sides of the side walls 6.

[0036] The traction means 18 are guided so as to revolve over two drying surfaces 13 in each case, which are disposed on top of one another. For this purpose, deflection wheels 19 are non-rotatably disposed in the first container 9 and in the last container 10, on a rotatably mounted shaft 20 that is disposed transversely to the longitudinal direction L, about which the traction means 18 are deflected, so that the traction means 18 are guided in one direction over one drying surface 13, and back over a drying surface 13 disposed therebeneath. The cross beams 16 are also deflected at the traction means 18, which is to say at one end of the drying surface 13 are transferred onto the rails 17 of an upper drying surface 13, and at another end of the drying surfaces 13 are transferred onto the rails 17 of the drying surface 13 disposed therebeneath. The shafts 20 comprising the deflection wheels 19 form deflections 21 of the linear conveyors 15. FIG. 1 shows a first container 9, in which the deflections 21 of the linear conveyors 15 at one end of the device 1 and of the drying surfaces 13 can be seen.

[0037] The linear conveyors 15 are driven in each case at one of the shafts 20 by an electric motor or in another manner (not shown).

[0038] Pegs project downwardly and upwardly from the cross beams 16 of the linear conveyors 15 and serve as conveying elements 22, wherein the downwardly projecting conveying elements 22 end at a small distance of one or several millimeters, and preferably less than 1 cm, above the respective drying surface 13. Conveying elements 22 that make contact with the drying surfaces 13 and pass over the drying surfaces 13 are also possible. After deflection, the upwardly projecting conveying elements 22 project downwardly toward the drying surface 13 then located therebeneath.

[0039] The conveying elements 22 can also comprise transversely or obliquely positioned plates, paddles, plow blades or the like for loosening, turning, distributing transversely across the width of the drying surface 13, and conveying the sewage sludge in the longitudinal direction L (not shown).

[0040] During the movement of the cross beams 16 in the longitudinal direction L, the conveying elements 22 “plow through” the sewage sludge, distribute it across the width B of the drying surfaces 13, turn it, loosen it, and successively convey the sewage sludge in the longitudinal direction L over the drying surfaces 13. The linear conveyors 15 can be operated continuously or with interruptions.

[0041] The conveying elements 22 are disposed spaced apart, next to one another, at the cross beams 16, wherein the conveying elements 22 are laterally offset at a cross beam 16 and, as seen in the longitudinal direction L, are thus disposed in gaps between the conveying elements 22 of another cross beam 16. FIG. 3 shows, by way of dotted lines, conveying elements 22 of another cross beam 16 which are disposed in the gaps between the conveying elements 15 of a cross beam 16.

[0042] In the first container 9 and in the last container 10, the drying surfaces 13, on which the sewage sludge is conveyed to the respective end, terminate in front of the respective drying surfaces 13 disposed therebeneath, on which the sewage sludge is conveyed back, so that, at the end of one drying surface 13, the sewage sludge drops onto the drying surface 13 disposed therebeneath.

[0043] The first and uppermost container 9 of the device 1, which is shown in FIG. 2, includes an opening as a loading point 23 for the sewage sludge in the ceiling 8 thereof. The first and lowermost container 9 can likewise include an opening in the floor 7 thereof, serving as a discharge point 24 for the sewage sludge, or the sewage sludge drops out of the first and lowermost container 9 from the lowermost drying surface 13 at the end face. In the exemplary embodiment, the first and lowermost container 9 comprises a cross channel 25, into which the sewage sludge drops at the end from the lowermost drying surface 13, and a screw conveyor 26, which is disposed in the cross channel 25 and by way of which the sewage sludge is removed from the device 1 through an opening in the side wall 6 of the container 9, serving as a discharge point 24.

[0044] In the exemplary embodiment, the slabs 12, the upper sides of which form the drying surfaces 13, are made of concrete, which is reinforced with glass fibers, synthetic fibers and/or stone fibers. The fibers form a rust-proof reinforcement 27 for the slabs 12. Since the reinforcement 27 does not rust, this does need to be covered by the concrete, as does a rusting steel reinforcement. The slabs 12 can therefore be thin.

[0045] The slabs 12 comprise pipes, as the heating lines 28, which are connected to one another in the intermediate spaces between the slabs 12 by sleeves, corrugated pipes or the like. In general, the heating lines 28 in the slabs 12 can also be interpreted as a heating device 29 of the drying surfaces 13. The slabs 12 are placed onto L profiles 30, which are attached to the insides of the side walls 6 of the containers 2 forming the modules 3 of the device 1 according to the invention.

[0046] The slabs 12 comprise transversely extending binding girders 31 for stiffening. In the exemplary embodiment, the slabs 12 additionally comprise longitudinally extending binding girders 31. The binding girders 31 can also run obliquely (not shown).