DEVICE AND COMPACT PLANT FOR DRYING, ESPECIALLY BIOMASS

Description

[0001] The invention relates to a device for drying material, in particular for drying moistened or moisture-containing mass or sludge, or moistened or moisture-containing parts or granules, such as metal shavings or wood chips. The invention particularly relates to a device for drying biomass, such as sewage sludge, milk sludge, brewer's spent grains, digestate, liquid manure, animal manure, or biogas slurry. The invention further relates to a compact system comprising one or more such drying devices.

[0002] To dry sewage sludge, it is known to distribute it as evenly as possible on a drying surface and then dry it, particularly under the influence of solar radiation. It can be particularly helpful to apply the biomass in layers to the drying surface. The drying process typically takes place in suitable buildings, which are usually designed like halls or greenhouses and are accordingly large. The drying surfaces in known systems can, in particular, be more than 100 meters long.

[0003] Various devices are known from the prior art that are designed to spread biomass, in particular sewage sludge, in a single plane on a drying surface. DE 103 11 554 B4, for example, describes a device with a scraper conveyor whose scrapers are guided at a defined distance from the drying surface to distribute sewage sludge in a defined layer thickness. To support the drying process under the influence of solar radiation, the drying surface can also be heated. Another drying device is known from DE 1604862.

[0004] The invention is based on the object of providing a new device for drying material, in particular biomass, for example sewage sludge, in which in particular a good mixing of the material applied to the drying surface, in particular the biomass, is ensured.

[0005] This object is achieved by a device having the features of claim 1. Advantageous embodiments and further developments are specified in the dependent claims.

[0006] The drying device according to the invention is designed in particular for drying materials such as moistened or moisture-containing mass or sludge or moistened or moisture-containing parts or granules, such as metal shavings or wood chips, or biomass, such as sewage sludge, milk sludge, brewer's spent grains, digestate, liquid manure, animal manure or biogas slurry. The drying device according to the invention comprises at least one drying surface (also: drying surface, drying level) onto which moisture-containing material, in particular biomass, can be applied flatly for drying. For applying and / or conveying the material, in particular the biomass, conveying elements movable or moved by at least one traction means are provided, which are attached to the at least one traction means at least indirectly, for example via at least one carrier arranged therebetween, and can be moved by the latter in the conveying direction.

[0007] According to the invention, the conveying elements for mixing the material on the at least one drying surface are mounted so as to be rotatable with respect to the at least one traction means about at least one axis of rotation running perpendicular to the conveying direction.

[0008] The formulation that the conveying elements are mounted rotatably with respect to the at least one traction means about at least one axis of rotation running perpendicular to the conveying direction should be understood in particular to mean that all conveying elements on a traction means or a plurality of the conveying elements on a traction means are rotatable about a common axis of rotation or that individual conveying elements, in embodiments all conveying elements of the respective device, are rotatable about axes of rotation that are individually assigned to the respective conveying element. In embodiments, a rotatable bearing is understood in particular to mean a bearing that enables rotation of the respective conveying element about the respective axis of rotation over an angular range of 360°, i.e. in particular continuous rotation of the conveying elements.

[0009] The conveying elements act to distribute and mix the material on at least one drying surface. The phrase "the conveying elements act on or toward the drying surface" is intended to refer in particular to any mechanical intervention suitable for distributing the material to be dried, in particular the biomass to be dried, on the respective drying surface and / or, if appropriate, for mixing it on the respective drying surface.

[0010] Terms such as "top," "bottom," "vertical," or "horizontal" should be understood in the context of this specification in the conventional sense with reference to the Earth's gravitational field. The drying surface typically extends substantially in a horizontal plane. In embodiments, several drying surfaces are provided, for example, at least one upper and one lower drying surface, which in advantageous embodiments are arranged one above the other and at least partially overlapping. In embodiments, the upper and lower drying surfaces extend substantially over horizontal planes spaced apart from one another in the vertical direction, which do not necessarily have the same dimensions and can be arranged offset from one another. In other embodiments, the upper and / or lower drying surfaces can be arranged, for example, slightly inclined with respect to a horizontal plane.

[0011] The conveying elements that can be moved or are moved by the at least one traction means are structurally designed such that they are suitable for distributing and, if necessary, aerating the material on the at least one drying surface. For this purpose, different structural designs of the conveying elements are possible in principle. In particular, the conveying elements can be designed, for example, as paddles, rakes, tines, hooks, turning hooks or shares, in particular ploughshares or duckfoot shares. In some embodiments, the conveying elements are designed, for example, as turning hooks and can, in particular, each have at least one turning section for distributing the biomass on the drying surfaces.

[0012] The conveyor elements are at least indirectly attached to the at least one traction means. Indirect attachment of the conveyor elements to the traction means is understood to mean, in particular, an attachment in which a fastening part, such as a support or a cross member supporting a plurality of conveyor elements, is arranged between the traction means and the conveyor elements. Such a cross member with a plurality of conveyor elements can be designed, for example, as a carrier rake.

[0013] Essentially, it is proposed to set the conveying elements in rotation as they move across the at least one drying surface in the conveying direction in order to improve the mixing of the material to be dried. Thus, the conveying elements are not guided uniformly across the at least one drying surface during drying operation of the device.

[0014] In some embodiments, the at least one drying surface can be heated at least partially, preferably completely, in particular by means of a heating device. The heating device is designed, for example, similar to an underfloor heating system and, in advantageous embodiments, can be at least partially, in particular completely, integrated into the drying surface.

[0015] In possible embodiments, the at least one drying surface is realized by a plate made of metal, in particular of stainless steel.

[0016] In some embodiments, the at least one traction means is an endless traction means, in particular a revolving traction means, for example a revolving rope, a revolving belt, a revolving strap, or a revolving chain. The traction means are preferably driven by conventional drives, such as electric motors.

[0017] At least some of the conveying elements are attached to the at least one traction means via at least one support. The conveying elements are movable by the traction means in the conveying direction. The at least one support can extend transversely to the conveying direction and / or several conveying elements can typically be attached to each support.

[0018] In advantageous embodiments, it is particularly provided that the conveyor elements and / or supports are suspended or fastened to a plurality of traction means for reasons of mechanical stability. In advantageous embodiments, each support is designed to carry a plurality of conveyor elements that are spaced apart from one another in a lateral direction transverse to the conveying direction. The conveyor elements spaced apart from one another in a lateral direction transverse to the conveying direction can, in particular, be regularly or irregularly spaced from one another. The spacing of the conveyor elements from one another is, in particular, selected such that they can move freely around their respective assigned axes of rotation during operation.

[0019] By dimensioning the supports and correspondingly adjusting the number of conveying elements that each support carries, it is possible in particular to specify devices that are designed to uniformly distribute material, in particular biomass, onto drying surfaces of different sizes.

[0020] The at least one support is arranged in a horizontal plane.

[0021] In embodiments, the conveying elements are mounted on the at least one carrier so as to be rotatable about axes of rotation running perpendicular to the conveying direction.

[0022] Alternatively (not claimed), the at least one carrier has a longitudinal axis extending transversely to the conveying direction and about which the at least one carrier is rotatably mounted. In such embodiments, the conveying elements attached to the carrier rotate with the carrier about its longitudinal axis.

[0023] In a further development of embodiments with at least one carrier mounted rotatably about its longitudinal axis, it is provided that the conveying elements are fastened to the at least one carrier in a rotationally fixed manner (not claimed).

[0024] According to the invention, the conveying elements are mounted eccentrically around vertical axes of rotation relative to the at least one traction means, such that the conveying elements are guided along cyclic curves (also known as cycloids or rolling curves) during the conveying movement over the drying surface, which extends, for example, in a horizontal plane. The conveying elements are thus not guided along linear trajectories over the drying surface, but rather describe curved paths to ensure thorough mixing of the material to be dried.

[0025] According to the invention, at least one of the conveying elements is coupled via a gear to a coupling element that is anchored stationary with respect to the conveying direction in such a way that the at least one conveying element can be set in a rotary movement by movement of the at least one traction means, i.e. by imparting a force acting along the at least one traction means. In this way, the conveying elements can be moved by means of the at least one traction means both in the conveying direction and rotated about the respectively assigned axis or axes of rotation. A separate drive for the rotary movement can thus be avoided. This ultimately means a structural simplification, since in particular the complex laying of power and / or compressed air lines to the concurrently moving conveying elements can be avoided.

[0026] According to the invention, the transmission is designed as a gear transmission. The transmission comprises, for example, at least one gear that engages with the stationary coupling element. The gear is connected to the carrier in a rotationally fixed manner, so that the carrier and thus the conveyor elements attached to it rotate with the gear.

[0027] In embodiments, the coupling element comprises a chain or toothed rail or rack extending at least in sections along the conveying direction.

[0028] In embodiments, the coupling element, in particular the chain or toothed rail or rack, is arranged in a fixed manner in space, in particular with respect to the at least one drying surface.

[0029] The compact system according to the invention for drying material, in particular for drying wood chips, metal shavings, or biomass, such as sewage sludge, milk sludge, brewer's spent grains, digestate, liquid manure, animal manure, biogas manure, or the like, comprises at least one of the devices described above. In advantageous embodiments, several of the devices described above are provided in a compact system. In such embodiments, such a compact system comprises at least two, preferably at least three, and particularly preferably four such devices. In advantageous embodiments, the devices are arranged vertically one above the other, in particular such that the material to be dried can be distributed in a cascade-like manner over the drying surfaces of the individual devices arranged one above the other.The compact system with its devices arranged on multiple levels allows for drying of the material conveyed by the devices on multiple drying surfaces or levels that are spaced apart vertically. This allows for better utilization of the available installation space, particularly in the vertical direction.

[0030] In some embodiments, the devices are arranged vertically one above the other in such a way that the drying surfaces of the devices arranged one above the other overlap at least in sections. In specific embodiments, the drying surfaces of the devices arranged one above the other are arranged so as to overlap at least to a large extent, for example, by more than 80%, in order to ensure better use of space. The overlapping arrangement should be understood in particular with regard to the space requirement of the respective drying surface with respect to a vertical projection onto a horizontal plane.

[0031] The invention will be explained in more detail below with regard to further features and advantages by means of the description of exemplary embodiments and with reference to the accompanying schematic drawings. FIG 1 shows a compact system according to the invention with two devices according to the invention arranged one above the other for drying material, in particular biomass, in a cross-sectional view; FIG 2 shows a non-claimed device for drying material, in particular biomass, in a schematic side view; FIG 3 shows a device according to the invention for drying material, in particular biomass, according to an embodiment in a schematic top view.

[0032] Corresponding parts and components are provided with the same reference numerals in all figures.

[0033] FIG 1shows a building unit 100 in which a compact system 50 is installed, comprising two stacked devices 10 for drying material, in particular for drying biomass, such as sewage sludge, and optionally a vertical conveyor 40. The following description explicitly refers to the drying of biomass. It is understood that the device 10 or the compact system 50 is not limited to the drying of biomass. The device 10 or the compact system 50 is equally suitable, for example, for drying inorganic material, such as metal shavings, or bulk material, such as wood chips or the like.

[0034] Each device 10 has at least one drying surface 11, 12. In the exemplary embodiment shown and not to be construed as limiting, each device 10 has an upper drying surface 11 and a lower drying surface 12, which are spaced apart from one another in the vertical direction. The upper and lower drying surfaces 11, 12 in the illustrated embodiment are designed as heatable plates, for example made of stainless steel. Biomass can be applied flatly to the drying surfaces 11, 12 for drying; during operation, the elevator 40 conveys the biomass from a storage area 60 to the upper drying surface 11 of the upper device 10. The devices 10 are designed to distribute the conveyed biomass on the drying surfaces 11, 12 and, if necessary, to mix it thoroughly.For this purpose, each device 10 has traction means 14, for example a circulating chain or a circulating rope, to which conveyor elements 16 are directly or indirectly attached.

[0035] The drying surfaces 11, 12 of the compact system 50 form a drying section for the material to be dried and are preferably heatable at least in sections. Optionally, in a manner not shown in detail, a comminution device, for example a chopper, is arranged at the entrance to the drying section, for example in the area of ​​the elevator 40 or in front of the elevator 40, for comminuting the supplied, moist material. Alternatively or additionally, a comminution device, for example a cutting rake, for comminuting the dried material is arranged at the outlet side of the drying section, i.e. at the end of the lowest drying surface 12 of the Figure 1 arranged.

[0036] In other embodiments, the compact system 50 comprises only one device 10. In particular, devices 10 with only a single drying surface 11 can also be provided.

[0037] In the exemplary embodiment shown, the traction means 14 are arranged circumferentially around the upper drying surface 11 of the respective device 10 and can be set in a circumferential movement by motor-driven drive means 18, for example by motor-driven rollers or cylinders.

[0038] During conveying operation of the device 10, the conveying elements 16 are moved by the traction means 14 over the drying surfaces 11, 12 in the conveying direction F. Since the traction means 14 of each device 10 are arranged circumferentially around the respective upper drying surface 11 (also: drying level), biomass can be conveyed both over the upper drying surface 11 and over the lower drying surface 12 with the aid of the conveying elements 16 attached thereto directly or indirectly.

[0039] The conveying elements 16 are structurally designed such that, during conveying operation, they act on the biomass on the respective drying surface 11, 12 and, in particular, discharge and / or convey and / or mix it. The conveying elements 16 are rotatably mounted with respect to the traction means 14, so that, during conveying operation, they also rotate about axes of rotation running perpendicular to the conveying direction F.

[0040] FIG 2shows a non-claimed example of the device 10 for drying material, in particular biomass, in a schematic side view. The conveying elements 16 are indirectly attached to the traction means 14 via supports 20, which extend transversely to the conveying direction F and perpendicular to the plane of the drawing. The supports 20 are pivotable about their FIG. 2 extending longitudinal axes L. The conveying elements 16 are designed as tines and, in the illustrated embodiment, are arranged on opposite sides of the carrier 20 and fastened thereto in a rotationally fixed manner. During conveying operation, the conveying elements 16 thus rotate together with the carrier 20 in the manner of a rotating driver rake.

[0041] In the example shown, the traction device 14 is designed as a chain. The carriers 20 are attached to the traction device 14 and are moved by it in the conveying direction F over the drying surfaces 11, 12 during conveying or drying operation. Each carrier 20 is coupled via a gear 30 to a stationary coupling element 34, which in the illustrated embodiment is designed as a chain, into which a gear 32 connected in a rotationally fixed manner to the carrier 20 engages. Since the coupling element 34 is fixed stationary with respect to the drying surface 11, it moves in the reference system of the moving carriers 20 opposite to the conveying direction F. The engagement of the moving gear 32 with the stationary coupling element 34 therefore imparts a torque acting about the longitudinal axis L of the carrier 20, so that the carrier 20 is set into a rotational movement in the direction of rotation D during conveying operation.The direction of rotation of the rotational movement about the longitudinal axis L can be adapted in particular by the position of the coupling element 34 with respect to the rotational or longitudinal axis L, so that embodiments are equally possible in which the conveying elements 16 rotate over the drying surface 11 in or against the conveying direction F.

[0042] FIG 3 shows an embodiment of the device 10 in a plan view.

[0043] The view is directed vertically towards the drying surface 11. The mode of operation is similar to the example of the FIG. 2 However, the gear 32 attached to the traction means 14 is arranged in a horizontal plane and the conveyor element 16 is attached at its end to a support 20 which does not extend over the entire width of the underlying drying surface 11. The gear 32 engages - as in the embodiment of the FIG. 2- into the coupling element 34, so that the conveying movement in the conveying direction F generates a torque acting around the vertical axis of rotation A. During conveying or drying operation, the carrier 20 rotates with the conveying element 16 attached to it at its end around the axis of rotation A. Since the conveying element 16 is arranged eccentrically with respect to the axis of rotation A, the conveying element 16 describes

[0044] Superposition with the conveying movement on the drying surface F a cyclic curve Z, which in FIG. 3 is indicated by dashed lines. List of reference symbols

[0045] 10Device 11Upper drying surface 12Lower drying surface 14Traction means 16Conveyor element 18Drive means 20Carrier 30Gearbox 32Gearwheel 34Coupling element 40Elevator 50Compact system 60Warehouse 100Building unit FConveying direction LLongitudinal axis DDirection of rotation ARotation axis ZCyclic curve (trajectory)

Claims

1. Device (10) for drying, in particular for drying biomass, comprising at least one drying surface (11, 12) onto which material, in particular biomass, can be spread in a planar manner for drying, wherein for spreading and / or conveying the material, in particular the biomass, conveying elements (16) are provided which can be or are moved by at least one traction means (14), which are attached at least indirectly to the at least one traction means (14) via at least one support (20), and which can be moved by said traction means in the conveying direction, wherein the conveying elements (16), for mixing the material on the at least one drying surface (11, 12), are mounted eccentrically with respect to the at least one traction means (14) so as to be rotatable about at least one rotation axis (A) extending perpendicularly to the conveying direction (F), such that the conveying elements (16) are guided along cyclic curves (Z) during the conveying movement over the drying surface (11, 12), wherein at least one of the conveying elements (16) is coupled via a transmission (30) to a coupling element (34), which is anchored in a stationary manner with respect to the conveying direction (F), such that the at least one conveying element (16) can be set into a rotary movement by movement of the at least one traction means (14), wherein the transmission is designed as a gear transmission, wherein the transmission comprises at least one gear wheel (32) which engages in the stationary coupling element (34), wherein the gear wheel (32) is connected to the support (20) in a rotationally fixed manner, and wherein the gear wheel (32) is attached to the traction means (14) and is arranged in a horizontal plane.

2. Device (10) according to claim 1, characterized in that the at least one support (20) is arranged in a horizontal plane.

3. Device (10) according to claim 1, characterized in that the coupling element (34) comprises a chain or toothed rail or toothed rack extending, at least in portions, longitudinally in the conveying direction (F).

4. Device (10) according to claim 3, characterized in that the coupling element (34), in particular the chain or toothed rail or toothed rack, is fixed in space, in particular with respect to the at least one drying surface (11, 12).

5. Compact system (50) for drying, in particular biomass, characterized by at least one device (10) according to any of the preceding claims.

6. Compact system (50) according to claim 5, characterized by at least two devices (10), preferably at least three devices (10), particularly preferably four devices (10), according to any of claims 1 to 4, wherein the devices (10) are arranged one above the other in the vertical direction.

7. Compact system (50) according to claim 6, characterized in that the devices (10) are arranged one above the other in the vertical direction such that the drying surfaces (11, 12) of the devices (10), which surfaces are arranged one above the other, overlap at least in portions.