WO2021028261A1

WO2021028261A1 - Apparatus and method for drying biomass with a high liquid content, in particular slurry

Info

Publication number: WO2021028261A1
Application number: PCT/EP2020/071875
Authority: WO
Inventors: Felix Hellmuth
Original assignee: Böhm Fertigungstechnik Suhl GmbH
Priority date: 2019-08-15
Filing date: 2020-08-04
Publication date: 2021-02-18
Also published as: EP4013721A1; DE102019122001A1

Abstract

The invention relates to an apparatus (10) for drying biomass with a high liquid content, in particular slurry, having a drying section via which the biomass for drying is able to be conveyed. The drying section comprises at least one closed drying surface (11a, 11b, 12a, 12b) over the area of which the biomass for drying can be applied. In order to apply the biomass to the at least one closed drying surface (11a, 11b, 12a, 12b) and to convey the biomass along the drying section, movable conveying elements (16) are provided. According to the invention, a mixing device (13), which is connected upstream of the drying section, is configured to thicken the biomass by adding dry granules. The invention also relates to a method for drying biomass with a high liquid content.

Description

Title: Device and method for drying biomass with a high liquid content, especially liquid manure

description

The invention relates to a device and a method for drying biomass with a high liquid content, in particular manure, for example animal manure and / or biogas manure, with a drying section via which the biomass can be conveyed to dry.

For drying sewage sludge, it is known to distribute it as evenly as possible in a plane on a drying surface and then to dry it, in particular under the influence of solar radiation. In this context, it can prove particularly helpful to turn the biomass applied in layers onto the drying surface one or more times during the drying process. The drying process typically takes place in buildings suitable for this purpose, which are designed in particular in the manner of a hall or in the manner of greenhouses and are correspondingly large. The drying area in known systems can in particular have lengths of more than 100 meters.

Various devices are known from the prior art, which are formed to apply biomass, in particular sewage sludge, in a plane on a drying area. DE 103 11 554 B4 describes, for example, a device with a scraper conveyor whose scrapers are at a defined distance from the

Drying surface are performed to distribute sewage sludge on this. To support the drying process under the influence of solar radiation, the drying surface can also be heated. DE 20 2019 101 031 U1 discloses a device for drying biomass, in particular sewage sludge, in which the biomass is conveyed with the help of conveying elements movable by means of Zugmit means along a drying section which, for example, has several drying surfaces arranged one above the other.

Sewage sludge has a relatively high dry content. The plants suitable for drying sewage sludge cannot generally be used directly for drying biomass with a high liquid content, such as liquid manure. In addition, liquid manure must not be drained, as the wastewater typically cannot enter the sewer system for regulatory reasons.

The invention is based on the object of specifying a new device and a new method for drying biomass with a high liquid content, in particular liquid manure.

With regard to the device, this object is achieved by the features of claim 1.

With regard to the method, this object is achieved by the features of claim 11.

Advantageous refinements and developments are specified in the dependent claims.

The device according to the invention for drying biomass with a high liquid content, in particular manure, for example animal manure and / or biogas manure, has a drying section via which the biomass can be conveyed to dryness. The drying section comprises at least one closed drying area (also: drying area, drying level), onto which biomass can be spread over a large area for drying. Movable conveying elements are provided for discharging the biomass on the at least one closed drying surface and for conveying the biomass along the drying section. According to the invention is a Mixing device, which is connected upstream of the drying section, designed to thicken the biomass by adding dry granulate.

Biomass with a high liquid content in the context of this description is in particular biomass with a dry matter content (also: dry matter content or dry matter content) of less than 15% (mass percentage, i.e. mass fraction of dry matter in relation to the total mass), for example about 5%. The mixing device can be a mixing container, thickener or the like. The mixing device is preferably net angeord at the entrance of the drying section. For evenly mixing the relatively liquid biomass with dry granulate, the mixing device can in particular have an agitator. In embodiments, the drying section comprises one or more closed drying surfaces arranged one after the other in the conveying direction. A closed drying area is understood to mean, in particular, a liquid-tight drying area. In particular, a closed drying surface has no openings or the like, so that biomass with a high liquid content can also be distributed and conveyed and thus dried on it.

Sawdust or already dried biomass that does not contain any toxins can be used as dry granulate.

The biomass still to be dried is preferably thickened in the mixing device to a predetermined minimum dry content. For this purpose, the device in or on the mixing device can have a measuring device for determining the dry content, which preferably interacts with a control device of the mixing device, in particular the addition of dry granulate.

In embodiments, at least one sensor detects the supply of dry granulate and / or biomass into the mixing device, preferably volumetrically. The at least one sensor is provided, for example, in the mixing device or on the feed for dry granulate and / or for biomass to be dried with a high liquid content of the mixing device. In an embodiment of the invention, the mixing device can comprise at least one doser for supplying the dry granulate and / or at least one doser for supplying the biomass to be dried with a high liquid content.

For example, the mixing device can comprise a carousel dispenser with several, for example three or four chambers, which are arranged, for example, on a circular base plate, separated from one another by partition walls and open at the top for filling. This carousel doser can work as follows, for example: A first chamber of the carousel doser is initially facing a feed device, for example a doser, for biomass to be dried, so that the first chamber is filled with biomass to be dried, preferably dosed volumetrically. The carousel feeder then rotates by a predetermined and / or adjustable angle of rotation so that the first chamber faces a feeder for the supply of dry granulate, so that dry granulate, preferably dosed volumetrically, from a feeder for the feed of dry granulate into the first chamber is given until a predetermined or set addition volume is reached. At the same time, a second chamber is now facing the feed device for biomass to be dried and is filled with biomass, as described above when filling the first chamber. The carousel feeder then rotates again by a predetermined and / or adjustable angle of rotation, so that the first chamber now faces an extraction point for the thickened biomass for transfer to the drying section. In refinements, a chamber can also face several metering devices for dry granulate and / or several adding devices for biomass to be dried one after the other.

For example, the mixing device can also comprise a screw feeder. This can work, for example, as follows: The screw conveys dry granulate from a screw inlet to a screw outlet, in particular volumetrically dosed. For this purpose, an addition for dry granulate can be arranged at or near the entrance of the Schneckendo sierers, for example a special volumetric addition meter for dry granulate. Along the conveyor route of the screw feeder is at one or more points from the side Biomass to be dried is added, for example via, in particular, volumetric dispensers, so that the biomass is mixed with the dry granulate on the further conveying path. At the exit of the screw feeder, the thickened biomass is transferred to the drying section.

In embodiments, a control device controls or regulates the supply of dry granulate and / or biomass with a high liquid content in the mixing device in such a way that the thickened biomass has a predeterminable minimum dry content. In embodiments, the control unit is connected in particular to the aforementioned sensor, which is used in the context of a control system or a control circuit to detect the amount of dry granulate and / or biomass supplied with a high liquid content. The supply of dry granulate and / or biomass with a high liquid content is preferably carried out in particular via a controllable supply device.

In refinements, a return device is designed to take up dried biomass at the exit of the drying section and to feed it to the mixing device as dry granulate. In other words, it is thus provided that previously dried biomass is used as dry granulate for thickening the liquid biomass that has yet to be dried. The return device removes getrock designated biomass at the exit of the drying section and feeds it to the mixing device, which is connected upstream of the drying section. In this way, a part of the cycle is formed with specially produced dry granulate so that external contamination can be avoided.

The dried biomass, in particular an excess of dried biomass that is not used as dry granulate, can serve as fertilizer. In this way, it is possible to dispose of manure from agriculture easily.

In embodiments, a removal device is designed to take random samples of the dried biomass, in particular at the exit of the drying section. to take. The samples can for example be examined in a laboratory with regard to the toxins they contain. The taking of such random samples is used for quality assurance.

The conveying elements for discharging the biomass are in configurations of at least one traction means movable or moved conveying elements which are directly or indirectly attached to at least one traction means and can be moved by this in a provided conveying direction.

The indirect attachment to the at least one traction means can be implemented, for example, via carriers. In configurations, the carriers extend transversely to the conveying direction and, in particular, several Förderele elements can be attached to each carrier.

The conveying elements can be designed as paddles, rakes, rakes, tines, hooks, turning hooks or shares, in particular plow shares or goosefoot shares. The conveying elements are designed as turning hooks, for example, and can each have at least one turning section for distributing the biomass on the drying surfaces.

The conveying elements are arranged at a distance from one another with respect to a conveying direction predetermined by the at least one traction means. The conveying elements spaced apart from one another in the conveying direction can, in particular in advantageous embodiments, be regularly spaced from one another. In configurations in which the conveying elements are designed as turning hooks, each turning hook preferably has at least one turning section for penetrating into the biomass to be applied or applied to the drying surfaces. The conveying elements or turning hooks can thus be moved in the conveying direction by the at least one traction means, wherein, for example, carriers extending transversely to the conveying direction can carry several turning hooks or conveying elements. In some embodiments, provision is made in particular to suspend or fasten the carrier to several traction means for reasons of mechanical stability. Each carrier is designed in particular to carry several conveyor elements or To wear turning hooks which are spaced apart from one another in the lateral direction transversely to the conveying direction. The turning hooks spaced from one another in the lateral direction transversely to the conveying direction can in particular be regularly spaced from one another. Through the dimensioning of the carrier and a corresponding adjustment of the number of turning hooks that each carrier carries, devices can in particular be specified that are designed to uniformly apply biomass to drying areas of different widths and / or to biomass that has already been applied to the at least one drying area Mix well to support the drying process.

The length of the at least one drying area should be understood to mean in particular the extent of the drying area along or parallel to the conveying direction. The width of the at least one drying area is to be understood as meaning, in particular, the extent of the drying area transversely or perpendicular to the conveying direction.

In refinements, the at least one turning section of the turning hook is designed to be curved. The at least one turning section can in particular have the shape of an elongated C or an elongated S. The curved shape of the at least one turning section serves in particular to mix or turn the biomass that has already been applied to the at least one drying area in order to promote the drying process.

In refinements, at least one of the supports has a hollow profile, which consists in particular of a metal, a light metal, a metal alloy or a light metal alloy. The design of the carrier as a hollow profile enables a weight reduction in an advantageous manner. In specific exemplary embodiments, the hollow profile can consist of steel, aluminum or an aluminum alloy, for example.

In refinements, the conveying elements or turning hooks, which carry at least one of the carriers, are fastened to the carrier in a rotationally fixed manner. In this way, the conveyor elements or turning hooks rotate about their axes during the conveyor operation prevented, so that in particular a good mixing of the already layered biomass applied to the at least one drying surface can be ensured.

In refinements, for the non-rotatable attachment of the conveyor elements or Wen dehaken these are provided with a non-rotationally symmetrical cross-sectional area, which are received in complementary recesses in the carrier. A rotationally fixed connection embodied in this way is particularly robust with regard to contamination by biomass and can therefore ensure the rotationally fixed anchoring of the turning hook even over longer periods of use.

In embodiments, the conveying elements or turning hooks are designed with vertical play such that they can be in direct contact, in particular in frictional contact, with the at least one drying surface during conveying operation. In other words, the conveyor elements or turning hooks are fastened to the carriers already described above, for example, in such a way that the conveyor elements or turning hooks have a certain amount of free space in the vertical direction. Since the conveyor elements or turning hooks are provided and designed to be guided over the at least one drying surface in grinding or rubbing contact during conveyor operation, the play can cause unevenness or manufacturing tolerances, in particular with regard to the structure of the drying surface, such as its waviness to be balanced.

Alternatively or additionally, the conveying elements or turning hooks are resiliently mounted in such a way that they can be in direct contact, in particular in rubbing contact, with the at least one drying surface during conveying operation. For this purpose, the conveyor elements or turning hooks are pretensioned in the vertical direction, for example by means of spring elements such as helical or leaf springs, so that they can act in particular downwards on the at least one drying surface. This measure, too, can compensate for unevenness or manufacturing tolerances, in particular with regard to the structure of the at least one drying surface, such as its waviness. In embodiments, the device comprises at least one closed upper and one closed lower drying surface, which are spaced apart from one another in the vertical direction. Biomass for drying can be spread over a large area on the upper and lower drying surface. In order to apply the biomass to the upper and lower drying surface, the aforementioned conveying elements or turning hooks are provided, which can be moved with the aid of at least one traction means. The one or more traction means is or are arranged in particular circumferentially around the upper drying surface. The totality of the drying surfaces form at least part of the drying section of the device.

It was recognized that conveyor elements or turning hooks that can be moved or moved by traction means can in principle be used to apply biomass to be dried onto two drying surfaces that are vertically spaced apart from one another when the traction device runs around the upper drying surface. The drying surfaces can in particular form two horizontal planes arranged one above the other. The conveying elements or turning hooks directly or indirectly attached to the traction mechanism move over the drying surfaces, so that biomass can be distributed over the drying surfaces and conveyed along the drying section. The conveying elements or turning hooks are accordingly designed to act in the direction of the upper and / or lower drying surface. This can be done, for example, through a suitable structural design and / or alignment of the conveyor elements.

In configurations in which the conveyor elements or turning hooks are rigidly attached to the traction means (the phrase "rigid" allows play of the conveyor elements or turning hooks, in particular vertical play to compensate for unevenness on the associated drying surface), these are for example with regard to the vertically aligned differently, so that they each act on the (upper and lower) drying surface below with respect to the moving conveyor elements when circulating around the upper drying surface. Alternatively or additionally, conveyor elements or turning hooks can also be provided, which are structurally designed so that these always act upwards and downwards.The conveying element or the turning hook can, for example, be a structure for this purpose have, which extend on both sides of the circumferential contour or circumferential plane which is defined by the revolving traction means or the revolving traction means. This can be realized in particular by a structurally symmetrical design of the conveying element or turning hook with respect to the traction means. Such conveyor elements or turning hooks are thus structurally designed so that when they circulate around the upper drying surface, they act at least on the (upper or lower) drying surface below with respect to the moving conveyor elements or turning hooks.

Alternatively or additionally, turning hooks or conveyor elements can be provided that are not rigidly or rigidly connected to the pulling element, but are attached to the pulling means indirectly or directly flexibly, for example via a joint, so that these conveyor elements or turning hooks especially when running around the upper drying area always act on the (upper and lower) drying level below with respect to the moving conveyor elements or turning hooks. The alignment of the conveyor elements or turning hooks connected in particular to the at least one traction means can for example take place under the action of gravity, so that the conveyor elements or turning hooks fold over in terms of their alignment with respect to the vertical axis, i.e. in the vertical direction, when rotating around the upper drying surface .

The wording that the conveying elements or turning hooks act on or in the direction of the drying surface should be understood to mean in particular any mechanical intervention that is suitable for distributing the biomass to be dried on the respective drying surface and / or in the conveying direction along the To promote the drying section and / or, if necessary, to mix it on the respective drying area.

Terms such as "above", "below", "vertical" or "horizontal" should be understood in the context of this specification in the conventional sense with reference to the earth's gravitational field. In this sense, the upper and lower drying areas are arranged one above the other at least in sections, ie they overlap at least at least partially. In embodiments, the upper and lower drying surfaces extend essentially over horizontal planes which are spaced apart from one another in the vertical direction and which do not necessarily have the same dimensions and can be arranged offset from one another. In other configurations, the upper and / or lower drying surface can be arranged, for example, slightly inclined with respect to a horizontal plane. In yet other Ausgestaltun conditions, only a single drying surface is provided, which preferably extends in a horizontal plane.

An indirect fastening of the conveyor elements or turning hooks on the train means is to be understood in particular as a fastening in which a fastening part, such as a cross member that carries several conveyor elements, is arranged between the tensioning means and the conveyor elements or turning hook. Such a cross member with several conveying elements can be designed, for example, as Mitnehmerre chen, the conveying elements or turning hooks can be prongs.

The circumferential contour or the circumferential plane should in particular denote that circumferential contour or that circumferential surface along which the at least one traction device or the provided traction device moves or move in the conveying mode.

The drying surface or the drying surfaces are realized in advantageous embodiments by plates made of metal, in particular made of stainless steel. The drying areas form at least part of the drying section over which the biomass is conveyed for drying. The drying surfaces of the drying section are designed to be closed, i.e. H. there are no breakthroughs or the like, so that biomass with a high liquid content can be dried.

In embodiments, the turning sections of the turning hooks, which are provided for distributing and / or mixing the biomass to be dried on the upper drying surface, with regard to the vertical direction or with regard to the circumference Running level (or circumferential contour) opposite to the turning sections angeord net, which are vorgese hen for distributing and / or mixing the material to be dried, in particular the special biomass to be dried, on the lower drying surface. In other words, turning hooks can be provided which are formed and aligned to act on or in the direction of the upper drying surface. Accordingly, turning hooks can be provided which are designed and aligned to act on or in the direction of the lower drying surface. The turning hooks can be designed in configurations in particular in the manner of double hooks and thus have both first and second turning sections that extend in opposite directions, in particular on both sides of the circumferential contour or plane that is defined by the circumferential traction means or the circumferential traction means . Such turning hooks we therefore ken during the revolving movement both on or in the direction of the upper and lower drying surface.

In refinements, turning hooks arranged adjacently in the conveying direction are each arranged alternately with their turning sections with respect to the vertical direction and / or with respect to the plane of rotation. In other words, the hooks that are arranged adjacently in the conveying direction are arranged or aligned alternately with regard to their alignment with respect to the vertical direction (or with respect to the circumferential contour or circumferential plane). The turning hooks, which are arranged adjacent in the conveying direction, can in particular be rotated by 180 ° or arranged mirror-symmetrically with regard to the circumferential contour or circumferential plane, which is defined by the revolving traction means or traction means. In this way it is achieved that the turning hooks, which are provided for acting on the upper drying surface, and those turning hooks, which are provided for acting on the lower drying surface, are arranged at least approximately evenly distributed along the conveying direction or along the plane of circulation are. This can in particular ensure an essentially uniform conveying operation. In refinements, at least one of the carriers carries several conveyor elements or turning hooks. For example, the turning hooks, which are attached to at least one of the carriers and are arranged adjacent to the conveying direction transversely, are provided with turning sections which are alternately arranged with respect to the vertical direction and / or with respect to the plane of rotation. In other words, in refinements, the turning hooks, which are arranged adjacent along the at least one carrier, are arranged or oriented alternately with regard to their orientation with respect to the vertical direction or the plane of rotation. The turning hooks, which are arranged adjacently along the at least one carrier, can, in particular with respect to the at least one carrier, each rotated by 180 ° or can be arranged mirror-symmetrically to this. In this way, it is sufficient that the turning hooks, which are provided for acting on the upper drying surface on the at least one carrier, and those turning hooks, which are provided for acting on the lower drying surface on the at least one carrier, along the at least one The carrier are arranged at least approximately evenly distributed. This can in particular ensure an essentially uniform conveying operation.

In embodiments, at least one of the turning hooks is designed as a double hook in such a way that it has a first and a second turning section which are arranged opposite one another with respect to the vertical direction. The first and the second turning section extend in particular on both sides and in opposite directions from the circumferential contour or circumferential plane which is or will be defined by the revolving traction means or the revolving traction means. Such turning hooks are thus structurally designed in such a way that when they circulate around the upper drying surface they act at least on the (upper and lower) drying surface located below with respect to the turning hooks moved during conveying operation.

In embodiments, the length of the upper drying surface, that is, the expansion of the upper drying surface along or parallel to the conveying direction, is smaller than the expansion of the lower drying surface. In this way, in particular This simple way ensures that material, in particular biomass, gets from the upper drying surface to the lower drying surface during the conveying operation.

In advantageous embodiments, the conveyor elements can be moved with the aid of the device at least over the entire length of the at least one drying surface, in particular over the entire length of the upper drying surface.

In embodiments, the at least one drying surface can be heated at least in sections, preferably completely, by means of a heating device. The heating device is designed, for example, similar to underfloor heating and, in advantageous embodiments, can be at least partially, in particular fully integrated in the at least one drying area.

In embodiments, the at least one traction means is an endless traction means, in particular a revolving rope, a revolving belt, a revolving belt or a revolving chain. The traction means are preferably driven by common drives such as electric motors.

In refinements, at least one comminution device for comminuting the material conveyed via the drying surfaces is arranged on at least one of the drying surfaces, in particular at the end. Preferably, at least one comminution device is provided on the inlet side for comminuting the moist material yet to be dried and / or at least one comminution device is provided on the inlet side for comminuting the dried material. The shredding devices are designed, for example, as milling machines, shredders, choppers, Schneidre surfaces or the like.

In refinements, the drying section comprises several, in particular upper and lower, drying surfaces, which are spaced apart from one another in the vertical direction and are each designed to be closed. Movable conveying elements are provided for applying the biomass to be dried onto the drying surfaces and for conveying the biomass along the drying section. The In preferred embodiments, the device thus comprises several drying planes which are arranged one above the other in the vertical direction. In this way, the installation space available in the vertical direction can be better used for drying. The device is designed accordingly as a compact system and can advantageously be installed in building units with relatively small external dimensions. In this way, it is made possible in particular to integrate the device, which is designed as a compact system, into a building unit at the factory in order to then deliver it to the end customer as a unit. The individual drying areas of the compact system can in particular be arranged one above the other in horizontal planes. The compact system is designed in such a way that, during the drying process, the biomass is transported over the entirety of the existing drying surfaces, which accordingly form at least part of the drying section for the material to be dried.

In configurations in which several upper and lower drying surfaces are available, several traction means are provided for moving the Förderele elements, the traction means being arranged circumferentially around the respectively assigned upper drying area. As already described above, several conveying elements can be moved with the help of the Zugmit means surrounding the respective upper drying area, which ensure the transport of the biomass over the associated upper and the lower drying area below. For every two drying levels, only one circulating traction device has to be provided. The device for drying the biomass can be made particularly compact in this way, in particular with regard to the space required.

In embodiments, the device comprises a height conveyor for conveying biomass to the uppermost drying surface. From this drying area, the biomass to be dried can be conveyed in a particularly simple manner in the conveying mode to the drying levels below. The elevation conveyor is designed in particular to carry thickened biomass, for example manure mixed with dry granulate, for example animal manure or biogas manure, to promote. Elevator conveyors suitable for this purpose are designed, for example, as belt conveyors, trough chain conveyors, continuous conveyors or belt conveyors. In advantageous embodiments, the height conveyor comprises at least one conveyor belt.

In refinements, the upper and lower drying surfaces arranged one above the other are superimposed in such a way that they overlap at least for the most part, in particular more than 80%, in order to ensure better use of space. The superimposed arrangement is to be understood in particular with regard to the area requirement of the respective drying area with regard to a vertical projection onto a horizontal plane.

The invention also relates to a method for drying biomass with a high liquid content, in particular manure, for example animal manure and / or biogas manure. The method is carried out, for example, with the device according to the invention described above.

In the method according to the invention, the biomass is conveyed through a drying section by means of conveying elements. The drying section has at least one closed drying surface on which the biomass is brought to dry over a large area. According to the invention, the biomass to be dried is thickened by adding dry granules before the entrance to the drying section.

In embodiments, the biomass is thickened to a dry content of at least 15% before the entrance to the drying section. The biomass is preferably thickened to a dry content of more than 15% before it enters the drying section.

In some embodiments, the biomass is thickened by adding sawdust. Alternatively or additionally, dried biomass, in particular dried manure, for example animal manure and / or biogas manure, can be used as dry granulate. The biomass used as dry granulate can, in particular with the aid of the device according to the invention described above, in a previously pending drying process. In some embodiments, exclusively dried biomass is used as dry granulate. This has on the one hand that no dry granulate has to be purchased to operate the device for drying biomass with a high liquid content and, on the other hand, impurities, which are caused, for example, by dry granulate of low quality, can be avoided.

In embodiments, dried biomass is received at the exit of the drying section, which is added as dry granulate with biomass still to be dried, the biomass still to be dried mixed with dry granulate being subsequently fed to the drying section for drying.

In embodiments, in particular at the exit of the drying section, samples of dried biomass are taken and examined, in particular in a laboratory, for poisons and / or pollutants they contain.

The material to be dried is distributed over the at least one drying surface by means of the conveyor elements already mentioned. In advantageous embodiments, the thickened, but still to be dried biomass is distributed in a cascade-like manner over at least two drying surfaces, which are spaced apart from one another in the vertical direction and overlap at least in sections, in order to spread the material for drying over the at least two drying surfaces. At least one upper drying area and at least one lower drying area are therefore preferably provided, which overlap at least in sections such that the biomass can be conveyed from the at least one upper drying area to the at least one lower drying area with the aid of the conveying elements. The drying of the material is advantageously carried out on several levels, the drying surfaces preferably being heated.

The material is preferably conveyed from the at least one upper drying surface to the at least one lower drying surface under the influence of gravity. For example, at least a portion of the at least one is lower The drying surface is arranged below the end of the upper drying surface in such a way that the material conveyed by means of the conveyor elements over the at least one upper drying surface falls onto the underlying section of the at least one lower drying surface. In this way, biomass is distributed like a cascade over the drying areas. Preferably, several drying areas, ie in particular more than two drying areas, are arranged one above the other, as described above, so that the material for drying can be evenly distributed over a large number of drying areas in a particularly simple manner.

Preferably, the conveying elements for discharging the material are moved by at least one traction means that runs around the at least one upper drying surface. The conveying elements act to distribute the material on the at least one upper drying surface and the at least one lower drying surface.

The invention is explained in more detail below with regard to further features and advantages using the description of exemplary embodiments and with reference to the accompanying schematic drawings. Show it

FIG. 1 shows a device for drying biomass in a cross-sectional view;

FIG. 2 shows a turning hook for the devices shown in FIG. 1 for drying material, in particular biomass, in a cross-sectional view;

FIG. 3 the turning hook of FIG. 2 in a further sectional illustration;

FIG. 4 shows the turning hook of FIG. 2 in a perspective illustration;

FIG. 5 shows a building unit in which the device of FIG. 1 is installed as a compact system, in a perspective external view; FIG. 6 shows an alternative building unit in which the device of FIG. 1 is installed as a compact system, in a perspective external view.

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

1 shows a building unit 100 in which a compact system 50 is installed, which comprises a device 10 for drying biomass with a high liquid content, such as manure, for example animal manure or biogas manure, and a height conveyor 40.

The device 10 has two upper drying surfaces 11a, 11b and two lower drying surfaces 12a, 12b, which are spaced apart from one another in the vertical direction. The upper and lower drying surfaces 11a, 11b, 12a, 12b are formed in the illustrated embodiment as heatable plates, for example made of stainless steel. A first upper drying surface 11a is arranged directly above a first lower drying surface 12a. Correspondingly, a second upper drying surface 11b is arranged directly above a second lower drying surface 12b. The first drying surfaces 11a, 12a are arranged above the second drying surfaces 11b, 12b. On the drying surfaces 11a, 11b, 12a, 12b, thickened biomass can be spread over a large area for drying, which the elevator 40 during operation from a mixing device 13, which is located in a store 60 for the biomass to be dried, onto the first upper drying surface 11a promotes. The device 10 is designed to distribute the promoted biomass on the drying surfaces 11a, 11b, 12a, 12b and, if necessary, to mix it. For this purpose, the device 10 has revolving traction means 14, for example a revolving chain or a revolving rope, to which the conveyor elements 16 are directly or indirectly attached. The endless traction means 14 are arranged circumferentially around the upper drying surfaces 11a, 11b and can be set in a rotating movement by motor-driven drive means 18, for example by motor-driven rollers or cylinders.

During the conveying operation, the traction means 14 move along closed trajectories, which describe a plane of rotation U or contour. The circumferential plane U are shown in cross section in FIG. 1 shown. Since the traction means 14 are arranged circumferentially around the respective upper drying surface 11a, 11b (also: drying level), with the aid of the conveying elements 16 directly or indirectly attached to it, biomass can be used both over the upper drying surface 11a, 11b as well as over the immediately below lying, lower drying surfaces 12a, 12b are promoted. The conveying elements 16 are structurally designed and aligned in such a way that they act in the direction of the upper and / or lower drying surface 11a, 11b, 12a, 12b during the circumferential movement along the circumferential plane U. For this purpose, the conveying elements 16 can have a structure suitable for conveying biomass, for example, which extends on both sides from the plane of rotation U in opposite directions.

In other cases, for example, conveying elements 16 can be provided which have a structure suitable for conveying biomass and which extends only on one side from the plane U of circulation. Such conveying elements 16, acting in only one direction, are correspondingly fastened directly or indirectly to the traction means 14 in different orientations with respect to the vertical direction, so that with the aid of the device 10 biomass both over the upper drying surface 11a, 11b and over the lower drying surface 12a , 12b can be distributed. Such conveying elements 16 are preferably arranged alternately along the plane of rotation U with regard to their orientation.

The first upper drying surface 11a has along the traction means 14 (parallel to the conveyor direction) a slightly smaller extent than the first lower drying surface 12a. The second upper drying surface 11b also has a slightly smaller extension than that along the Zugmit tel 14 (parallel to the conveying direction) second lower drying surface 12b. The first lower drying surface 12a and the second upper drying surface 11b are arranged slightly offset from one another. In this way it is ensured that the biomass conveyed by the elevator 40 over a large area over the upper and lower drying surfaces 11a, 11b,

12a, 12b can be distributed.

Possible configurations of the conveyor elements 16 are shown in FIG. 2 to 4 shown.

The conveying elements 16 are designed in possible configurations in particular as turning hooks 20 which are carried by carriers 22 which are attached to the Zugmit means 14. Each carrier 22 extends transversely to the conveying direction and carries several turning hooks 20 which are aligned alternately with respect to the plane of rotation U (see FIG. 1), that is to say in particular alternately upwards and downwards.

The turning hook 20 comprises a curved turning section 24 for conveying biomass over the drying surfaces 11a, 11b, 12a, 12b. The turning section 24 is designed to rest at the end on the drying surfaces 11a, 11b, 12a, 12b and to be guided over the drying surfaces 11a, 11b, 12a, 12b in a dragging manner during the conveying operation. In order to ensure a continuous frictional contact of the turning hooks 20 with the drying surfaces 11a, 11b, 12a, 12b, these are attached to the carrier 22 with vertical play, i. H. the turning hooks 20 have a certain amount of clearance in the vertical direction, so that in particular unevenness in the drying surfaces 11a, 11b, 12a, 12b can be compensated for during the conveyor movement.

Alternatively or additionally, the turning hooks 20 are pretensioned in the vertical direction by means of spring elements (not shown) in the direction of the drying surfaces 11a, 11b, 12a, 12b, in order to ensure a largely sliding contact between the turning hooks 20 and the drying surfaces 11a, 11b, 12a, 12b during the conveying operation to ensure.

In order to counteract wear of the turning hooks 20, these are preferably at least partially made of wear-resistant material such as stainless steel educated. As an alternative or in addition, the turning hooks 20 have at least one end a covering made of wear-resistant material. This coating can, for example, be a stainless steel coating that covers at least the end region of the turning hook 20 which, when the device 10 is used as intended, is in contact with the conveyed material and / or in sliding contact with the drying surfaces 11a, 11b, 12a, 12b.

The number, the distance and the shape of the turning hooks 20 can in particular be adapted to the material to be dried. The device 10 is designed to be flexible in this regard and can be modified in order, for example, to enable the drying of biomass with different liquid contents.

In an alternative embodiment, the turning hooks are designed as double hooks in not dargestell ter manner and include first and second turning sections that are curved and protrude from the carrier 22 in opposite directions.

As shown particularly in FIG. 2 to 4, the turning hooks 20 are positively inserted into a recess 26 of the carrier 22 and secured at the end by means of a split pin 28 and a washer 30. In this way it is ensured that the turning hook 20 attached to the carrier 22 has clearance in the vertical direction and can also be exchanged quickly and easily. For example, the carrier 22 with the turning hook 20 can be designed as a driver rake with quick-change ble prongs.

The carrier 22 is designed as a hollow profile. The shape of the recess 26 is complementary to the cross-sectional shape of the inserted turning hook 22, which has a non-rotationally symmetrical cross-section in this area. The Wen dehaken 20 is thus attached to the carrier 22 in a rotationally fixed manner. In the exemplary embodiment shown, the turning hook 22 has a run on the core 32 in the region of the recess 26, from which two diametrically protruding ribs 34. As shown particularly in FIG. 2 or 4, one of the ribs 34 is slightly shorter in extent than the other. FIG. 5 and FIG. 6 each show, in an external view, the building unit 100 in various alternative configurations. The device 10 is installed in the building unit 100 as a compact system 50 (see FIG. 5). Such a building unit 100 can have a modular structure and contain a plurality of drying areas 11a, 11b, 12a, 12b arranged one above the other, which form at least part of the drying section for the goods to be dried. In one possible exemplary embodiment, eight drying surfaces 11a, 11b, 12a, 12b arranged one above the other are provided so that the drying process takes place on a total of eight drying levels. The compact system 50 is characterized by a reduced installation space requirement and can be installed in a building unit 100 whose length along the conveying direction is less than 30 meters, preferably less than 20 meters, particularly preferably about 15 meters and whose width transversely to the conveying direction is less than 5 meters, preferably less than 3 meters, particularly preferably about 2.5 meters and the height of which is less than 10 meters, preferably less than 8 meters, particularly preferably about 6 meters. Due to the small installation space requirement of the compact system 50, it can already be installed at the factory in a suitable building unit 100, which can then be delivered to a customer as an essentially already fully assembled system.

FIG. 6 shows, by way of example, various components of the building unit 100, namely a silo 101 for dry granulate, a moving floor container 102 for biomass to be dried, a suction system 103, a drying unit 104 and a control container 105. The drying granulate can be provided, for example, via one on the drying unit 104 Screw feeder (not shown) are conveyed in the direction of the drying unit 104. The biomass to be dried is introduced into the screw feeder via side feeds and mixed with the dry granulate, resulting in thickened biomass. The screw doser thus forms the mixing device, if necessary with other components. The thickened biomass is then fed to the drying unit 104.

The drying surfaces 11a, 11b, 12a, 12b of the compact system 50 form at least part of the drying section for relatively liquid biomass and are closed educated. To thicken the biomass to be dried, the mixing device 13 is connected upstream of the drying section. In the mixing device 13, biomass with a high liquid content and dry granulate are mixed, in particular in such a way that thickened biomass with a certain minimum dry content is produced. In FIG. 1, the supply of the biomass with a high liquid content from the store 60 to the mixing device 13 is symbolized by an arrow 71. The continuation of the thickened biomass to the drying section, specifically in the example shown to the elevator 40, is symbolized by an arrow 72. The mixing device 13 comprises, for example, a mixing container with a stirrer for stirring in the dry granulate. The supply of biomass and / or dry granulate to be dried into the mixing device can be controlled and, for example, can be measured volumetrically by means of at least one sensor 15. The sensor 15 is, in FIG. 1 symbolized by a line, connected to a control device 17. The control device 17 controls, in FIG. 1 symbolized by two lines, the supply of biomass to be dried with a high liquid content and of dry granulate in such a way that thickened biomass with a predetermined minimum dry content is formed. The thickened biomass is fed to the drying section for further drying.

The untreated biomass is, for example, liquid manure with a low dry content of in particular only 5%. The thickened biomass which is fed to the drying section for further drying has a dry content of at least 15%, preferably more than 15%. The biomass is thickened by adding dry granulate, for example flour or previously dried biomass.

A shredding device (not shown), for example a cutting rake, for shredding the dried biomass is arranged in possible configurations on the output side of the drying section, i.e. at the end of the second lower drying surface 12b (see in particular FIG. 1).

At the exit of the drying section there is, for example, a return device 19 in which at least part of the dried biomass is collected. The return device 19 is designed to feed the removed dried biomass to the mixing device 13 as dry granulate. The return device 19 comprises, for example, conveying means, such as a belt conveyor, which are designed to transport the dried biomass to the mixing device 13. The return of dried biomass as dry granulate for the mixing device 13 is symbolized in FIG. 1 by an arrow 70.

At the exit of the drying section a removal device 21 is also arranged, which is designed to take random samples of the dried biomass. The random samples taken are examined for toxins or pollution in a laboratory, for example.

List of reference symbols

10 device 11a upper drying surface 11b upper drying surface 12a lower drying surface 12b lower drying surface

13 Mixing device

14 traction means

15 sensor

16 conveyor element

17 Control device

18 drive means

19 feedback device

20 turning hooks

21 Withdrawal device

22 carriers

24 turning section 26 recess 28 split pin 30 washer 32 core 34 rib 40 elevator 50 compact system 60 warehouse

70 Return of dried biomass as dry granulate

71 Supply of biomass with a high liquid content

72 Continuation of thickened biomass

100 building unit

101 silo

102 moving floor container

103 suction 104 drying unit

105 control container

U revolving plane

Claims

1. Device (10) for drying biomass with a high liquid content, in particular liquid manure, with a drying section via which the biomass can be conveyed to dryness, the drying section having at least one closed drying area (11a, 11b, 12a, 12b) which can be spread over a large area for drying the biomass, wherein movable conveying elements (16) are provided for spreading the biomass on the at least one closed drying surface (11a, 11b, 12a, 12b) and for conveying the biomass along the drying section characterized in that a mixing device (13), which is connected upstream of the drying section, is designed to thicken the biomass by adding dry granulate to it.

2. Device (10) according to claim 1, characterized in that at least one sensor (15) detects the supply of dry granulate and / or biomass in the mixing device (13).

3. Device (10) according to claim 1 or 2, characterized in that a control device (17) controls or regulates the supply of dry granulate and / or biomass with a high liquid content in the mixing device (13) such that the thickened biomass has a predeterminable minimum dryness stop has.

4. Device according to one of the preceding claims, characterized in that a return device (19) is designed to receive getrock designated biomass at the exit of the drying section and to feed the mixing device (13) as dry granulate.

5. Device according to one of the preceding claims, characterized in that a removal device (21) is designed to remove sample samples from the dried biomass.

6. Device according to one of the preceding claims, characterized in that the conveyor elements (16) can be moved by means of at least one traction means (14).

7. The device (10) according to claim 6, characterized in that at least one upper and one lower drying surface (11a, 11b, 12a, 12b), which are spaced from one another in the vertical direction, are provided, wherein the at least one traction means (14) is arranged circumferentially around the upper drying surface (11a, 11b) and the upper and lower drying surface (11a, 11b, 12a, 12b) are designed to be closed.

8. Device (10) according to claim 6 or 7, characterized in that the at least one traction means (14) is an endless traction means, in particular a rotating rope, a rotating belt, a rotating belt or a rotating chain.

9. Device (10) according to one of claims 6 to 8, characterized in that the drying section of several upper and lower drying surfaces (11a, 11b, 12a, 12b), which are spaced apart in the vertical direction and are each formed closed , is formed and for spreading the biomass on the upper and lower drying surfaces (11a, 11b, 12a, 12b) and for conveying the biomass along the drying path movable conveyor elements (16) are provided.

10. The device (10) according to claim 9, characterized in that several traction means (14) are provided for moving the conveyor elements, each of the traction means (14) being arranged circumferentially around an upper drying surface (11a, 11b).

11. A method for drying biomass with a high liquid content, in particular special manure, wherein the biomass is conveyed by means of conveying elements (16) over a drying section, the drying section having at least one closed drying surface (11a, 11b, 12a, 12b) on which the biomass is applied over a large area for drying, characterized in that the biomass is thickened by offset zen with dry granulate before the entrance to the drying section.

12. The method for drying according to claim 11, characterized in that the

Biomass is thickened to a dryness of at least 15% before the entrance to the drying section.

13. The method for drying according to claim 11 or 12, characterized in that the biomass by adding S flour and / or with dried

Biomass, especially dried manure, is thickened.

14. The method for drying according to any one of claims 11 to 13, characterized in that dried biomass is received at the exit of the drying section, which is added as dry granulate with still to be dried biomass, the mixed with dry granulate, still to be dried biomass is then fed to the drying section for drying.

15. The method for drying according to one of claims 11 to 14, characterized in that random samples of dried biomass are taken and examined for toxins and / or pollutants contained.