EP0873286A1

EP0873286A1 - Device and process for the aerobic treatment of organic substances

Info

Publication number: EP0873286A1
Application number: EP96900941A
Authority: EP
Inventors: Erich Eigner
Original assignee: Interlicense Den Haag BV
Current assignee: Interlicense Den Haag BV
Priority date: 1996-01-11
Filing date: 1996-01-11
Publication date: 1998-10-28
Also published as: AU4485796A; WO1997025295A1; US6065224A

Abstract

The present invention relates to a device (1) for the aerobic treatment, conditioning and/or drying of moist, substantially solid or paste-like, preferably at least partly organic material, based on a vessel (2) containing paired, Venetian-blind-like walls (3a, 3b), with preferably adjustable blades (10, 10a, 10b), forming at least one reaction chamber (4), at least one air inlet chamber (5) and at least one air discharge chamber (6), and also containing supprots (8a, 8b, 8c, 8d), which are in spatially staggered array inside the reaction chamber (4) in such a way that they provide the best possible pressure relief for the filling. The invention also relates to a process using said device.

Description

Device and method for aerobic treatment of organic matter

TECHNICAL AREA

The invention relates to a device for aerobic treatment, hygienization and / or drying of moist, preferably at least partially organic, material of essentially solid or pasty nature, using a specific reactor geometry and special internal fittings. The device is particularly suitable for microbiological pretreatment, conditioning and / or sanitation of organic residues and other organic waste, in particular industrial and municipal sewage sludge, as well as waste from agricultural production, factory farming, horticulture and industrial food and beverage production, for the purpose of long-term stabilization the residues and / or for the production of organic and organo-mineral fertilizers, growing media and / or soil additives.

STATE OF THE ART

The closest prior art (AT 382 862 B) describes a method and a device for drying chicken manure or similar pasty substances. In a microbiological phase, selective microorganisms are settled on shaped, stable carrier elements, the pasty substances to be treated are fed into strand-like pellets after prior pressing and are suitable with conditioned air

Climatic conditions created for the activity of the microorganisms. The resulting heat and moisture is removed with the air flow. After the microbiological phase has ended, the remaining material is dried in a drying phase by flowing air through to the desired degree of drying. The device used for this purpose has a closed cylindrical container which contains two coaxially arranged, air-permeable cylinders made of perforated sheet metal, which can be vibrated vertically and contain support elements for the selective microorganisms between the perforated sheets. The supply and exhaust air lines and the blowers are installed in such a way that a centripetal air flow is forced from the inner wall of the container through the perforated plates to the center of the container, from where it is extracted from the container via the exhaust air line.

With this method it is possible to dry granulated, briquetted or shredded, pasty substances with the lowest possible energy through the use of microorganisms, which are concentrated on carrier elements. Ultimately, chicken manure from factory farms, for example,

ORIGINAL DOCUMENTS ride that the dried product in granular form comes from the drying process, can be stored without problems and can also be sold in supermarkets as a biological fertilizer. In addition to this, a small part of the organic but also inorganic substances contained in the process is converted by the microorganisms into CO2 heat and residues, which is an advantageous effect in that these organic substances are often undesirable in the end product because they are undesirable smell unpleasant and limit the shelf life of the dried end product.

Disadvantages of this system can be seen, inter alia, in the fact that the air flowing through only in one direction, namely centripetal, has a substantially larger entry area into the reaction space than exit area from the reaction space through this reactor geometry. This leads to the fact that, especially in the case of greater layer thicknesses of the reaction space, for example of more than 100 cm, the air speed at the outlet openings of the inner perforated plate cylinder becomes so high that it can transport small particles, especially in the drying phase, which can then be transported outside of the Deposit the reaction space in the bioreactor and have to be laboriously removed from there, otherwise they would cause undesirable odors.

The problem of the undesired escape of filling material from the reaction space also arises in the course of the filling process, where it frequently throws or presses particles through the holes in the perforated plate cylinder into the air space.

Another disadvantage of the known system is that especially in the bottom area of the reaction space, where the freshly filled organic material is most compressed, the exclusively horizontal air flow may no longer be sufficient to adequately sanitize and / or dry the material located there , which in addition to a loss of quality can also cause procedural difficulties (e.g. difficult discharge, odor pollution).

Another major disadvantage is the fact that the contents in the marginal zones of the reaction chamber, i.e. in the vicinity of the perforated plates, are not supported and therefore not relieved of pressure, so that there the material is compressed more and the air flowing through opposes a higher resistance, which affects both the treatment process itself and the required blower performance and thus the energy consumption. In contrast, the present invention has set itself the task of using the essentially the same microbiological and physical effects to create a device which, thanks to a significantly improved bioreactor geometry and in particular in cooperation with a modified mode of operation, the above-mentioned disadvantages of the closest prior art are impressive overcomes.

BRIEF DESCRIPTION OF THE INVENTION

This object is achieved according to the present invention by a device in which the interior of the round or square reactor vessel is not divided by perforated plate cylinders, but rather by air-permeable walls of a louvered lamellar structure arranged in pairs. These pairs of walls extend essentially over the entire height of the bioreactor container and are arranged such that the sides facing one another, i.e. the inner sides, of each pair form an intermediate reaction space, while the sides facing away from one another of such a pair, i.e. form the outside, air spaces. The slats are attached to the supporting structure at predetermined angles, distances, lengths and / or widths and are preferably mounted so that they can move, so that the angles of the slats can be changed, similar to conventional window blinds. Depending on the type of bioreactor, these lamella walls are rectilinear, curved or closed in a ring and are arranged in pairs to one another in such a way that they are at a substantially constant distance from one another over their entire length, which is achieved by at least approximately parallel or concentric arrangement.

BRIEF DESCRIPTION OF THE FIGURES

1 shows a schematic diagram of a two-dimensional frontal view of the device according to the invention with a pair of parallel lamella walls, with support elements, support elements and horizontal elements. 2A shows a schematic diagram for the preferred direction of air flow in a device with two reaction spaces and perforated container bottom; Arrows mark the direction of flow. 2B shows a schematic diagram of a two-dimensional frontal view of the device with filler and bottom flaps, support elements and a connecting line between the supply air and exhaust air lines. 3 shows a basic diagram of a horizontal cross section of a round embodiment of the device with a pair of concentrically arranged, annularly closed lamella walls with supporting elements; Arrows mark the preferred direction of air flow. Fig. 4 shows a schematic diagram of a horizontal cross section of a polygonal embodiment of the device with a pair of essentially concentrically arranged, annularly closed lamella walls with support elements; Arrows mark the preferred direction of air flow.

DETAILED DESCRIPTION OF THE INVENTION

In the simplest case, the bioreactor 1 consists of a container 2 with a square horizontal cross section and a single pair of internal, linearly designed lamella walls 3a, 3b. These lamella walls are preferably arranged plane-parallel to one another in order to ensure a uniform layer thickness of the reaction space 4 located therebetween. With their outer sides, they divide the interior of the container into two

Air zones that communicate with each other only via the reaction space. One air zone is the supply air area 5, into which fresh air, recycled exhaust air or other external air is supplied via at least one supply air line 7, while the other air zone is the exhaust air area 6, in which the air is collected after flowing through the reaction chamber 4 and via at least one exhaust air line 1 2 is withdrawn from the container.

The device according to the invention also contains support elements 8a, 8b, 8c, 8d and optionally support elements 9 which are arranged within the reaction space. The support elements serve the purpose of the best possible pressure distribution of the filling material, so that even on the particles of the filled organic material in the bottom area of the reaction space 4 there is an average maximum pressure which is lower than the corresponding pressure without these supporting elements with the same filling weight. This effect of the pressure reduction causes a loosened bed of the filling material in the reaction chamber 4 and is favored by the fact that the support elements 8a, 8b, 8c, 8d are spatially staggered both vertically and horizontally, which also prevents the formation of unwanted, continuous horizontal layers within the Hinder reaction space 4. Your horizontal, diagonal and vertical

The distance from one another is also such that, depending on their size, i.e. in particular their horizontal extension and a commercially useful number of such elements, the distances to the neighboring supporting elements are as minimal as possible, while the mutual weight support of the filled particles of the organic material - among other things via bridge effects - an optimum achieved. The relatively loose bed of the filling material thus obtained is accessible to a sufficient and largely uniform air supply in the entire reaction space 4. The use of suitable support elements 8a, 8b, 8c, 8d and optionally support elements 9 also prevents undesired zones of lower air resistance or inadequate air flow from being formed and thus reducing the performance of the reactor. Such undesirable effects could occur, for example, in the case of support elements which enclose air spaces which are not or only insufficiently filled by the filling material.

With regard to an optimal pressure distribution and pressure reduction, it has proven to be advantageous not to fill the support elements 8a, 8b, 8c, 8d loosely into the reaction space, but rather to fix them largely in a fixed manner in the horizontal and vertical direction. The spatial arrangement of the support elements can be achieved in a simple case, for example, by providing them with a bore and threading them onto a carrier element 9, for example a rope or a rod, like the pearls of a pearl necklace. The support elements, which are threaded onto a rope or a rod, are preferably kept separate from one another in the vertical direction by spacers, for example hollow cylinders of suitable dimensions threaded between them. The vertical distance between the support elements does not have to be constant over the entire length of a support element, but is advantageously less near the floor than in the head region of the reaction space. Due to the shorter spacing intervals and the resulting higher number of support elements in the lower, near-ground zones, the real pressure conditions are better taken into account and better pressure relief is achieved than with statistical uniform distribution of the support elements in the entire reaction space.

However, it must be taken into account that the spacers must be dimensioned such that on the one hand they do not create any undesirable cavities and on the other hand they can bear the weight of the support elements and the pressure on them. In addition, they must of course withstand the chemical and thermal loads that occur in the bioreactor.

For most applications, the support elements 8a, 8b, 8c, 8d are arranged one above the other at vertical intervals of about 10 to about 100 cm, in the case of compact and heavy contents at intervals of at most about 20 to about 50 cm. Their lateral spacing - measured as the lateral spacing of the imaginary vertical axes of two adjacent, spatially offset support elements - is, also depending on the filling density, the strength, porosity and the specific weight of the filling material and the size of the support elements preferably about 20 to about 80 cm, in particular about 30 to about 50 cm to each other. If there are vertical support elements with supporting elements attached to them, this corresponds to the distance between two adjacent, vertically attached support elements.

The size of the support elements 8a, 8b, 8c, 8d, which can be used expediently from an economic point of view, is mainly determined by their horizontal extension, i.e. their greatest width, measured, which ranges between about 5 and about 35 cm, but preferably between about 10 and about 20 cm.

In a preferred embodiment, the carrier elements 9 are fastened to a stable suspension device, for example a grating, in the head space of the container 2 and optionally also to a fastening element, for example also a grating, in the bottom area. It goes without saying that the suspension device in the head space and the fastening element in the floor area are designed such that they do not significantly impede the filling and / or emptying process for the material to be treated or finished.

It has proven to be advantageous for the economically optimal use of space of the device according to the invention. Only install support and, if necessary, support elements to such an extent that they together take up a maximum of about 0.5 to about 10%, but preferably only about 1 to about 6%, of the container volume. The support elements 8a, 8b, 8c, 8d essentially consist of symmetrically or asymmetrically shaped bodies which are suitable for exerting a loosening, supporting and pressure-distributing effect on the filling material. Cubes, cylinders, cones, plates, plates, spheres, spiral elements and similar three-dimensional bodies are suitable for this purpose.

It has proven to be a great advantage if the support elements 8a, 8b, 8c, 8d and / or possibly the support elements 9 are attached so that they can be moved vertically and / or horizontally, at least to the extent that they are coupled to a vibrating device. This measure also leads to breaks in material bridges that have built up between adjacent support elements and thus supports the internal material transport from top to bottom and the material discharge from the reaction space. In a particularly advantageous embodiment of the device according to the invention, at least some of the support elements 8a, 8b, 8c, 8d are designed in the form of vertically arranged spirals and / or screws 8b. The spirals have the geometry of spiral springs, ie they do not contain an internal axis and are either designed to be self-supporting or their pitch is stabilized by, for example, two external axes. The spirals can, however, also be designed such that their band-shaped spiral paths are interrupted in sections, pass into a rigid axis and then assume spiral form again. The screw elements 8b are support elements in the form of screw conveyors, which are likewise designed either with a continuous or partially interrupted spiral path. In both cases, the width of these band-shaped spiral tracks is between approximately 5 and approximately 35 cm, preferably between approximately 10 and approximately 20 cm. The overall diameter of such screw and spiral elements is between approximately 10 and approximately 90 cm at a pitch (= longitudinal distance between two identically oriented points on the spiral path after a 360 degree rotation) of the spiral path of approximately 10 to approximately 100 cm. The advantage of this type of support elements 8b lies in particular in the fact that, in addition to their supporting property, they transport material within the

Reaction chamber 4 and in particular effectively support the material discharge from the container 2, provided that they are rotatably mounted and connected to a drive motor which rotates them about their longitudinal axis at the desired time. As a result of the rotation of the spirals and / or screws 8b, existing bridges of the filling material, which have formed between adjacent supporting elements, are broken, as in the case of the vibration mentioned above, and thereby the slipping of the material into the lower regions of the reaction space 4 is supported.

In another embodiment, at least some of the support elements are designed in the form of louvered slat walls 8d, which preferably contain adjustable slats. They are preferably designed so that they extend approximately over the entire height, but at least over three quarters of the height of a reaction space 4. Advantageously, the slats can be adjusted in sections, for example in vertical sections of approximately 0.5 to approximately 1 m in height, both separately from one another and together in relation to the angle of attack. The number of such lamella walls 8d as support elements depends on the size of the entire device and on the layer thickness of the reaction space 4. In smaller systems, a single lamella wall 8d may be sufficient, but usually two to about fifteen such lamella walls, which can be arranged parallel or offset to one another, are present within a reaction space. Similar to the spiral or screw-like support elements 8b, it is also here possible to break material bridges by moving the lamellae and thus to ensure a uniform and / or accelerated further transport of the treated material within the reaction space 4 and / or for an improved discharge of the material from the container 2.

The lamella walls 3a, 3b, the lamellae 10, 10a, 10b of which are designed and fastened in such a way that their lower edges extend into the reaction chamber 4, while the upper edges of them make an important contribution to the support and pressure distribution of the filling material in the edge region of the reaction space Point the reaction space upwards into the air spaces 5, 6. In the simplest and most cost-effective embodiment, the slats 1 0, 1 0a, 10b are rigidly mounted at a desired angle of attack, for example inserted and welded onto a frame with grooves cut at the correct angle.

In the simplest case, the fins 10, 10a, 10b are designed in the form of straight, flat sheet metal strips with a thickness of approximately 0.2 to approximately 0.8 mm. However, it goes without saying that in order to achieve a better load-bearing capacity and torsional stiffness of the slats, convexly curved slats or pressed in a special profile shape can also be used. Also with regard to the material used, the present lamella construction, like the entire reaction vessel, is by no means limited to metal, in particular stainless steel, aluminum, or galvanized iron sheet. Rather, suitable plastics that can withstand chemical, thermal and mechanical loads, but also wood, can be used.

In an extremely powerful embodiment, in particular in large systems, the lamella construction consists of lamella walls 3a, 3b with several, preferably three to ten, but at least two horizontal and preferably also vertical sections, which together and / or independently of one another with respect to the angle of attack of the lamellae 10 , 10a, 10b can be set. In the horizontal direction, the division into two or more sections mainly takes into account the pressure load on the individual slats in order to prevent long slats having to be used which could bend or even permanently deform. Otherwise, this could, among other things, also lead to restricted rotatability of the slats in the movable embodiment and, in the case of both rotatable and rigid slats, cause or at least favor undesirable discharge of material from the reaction space into the air spaces. However, it also allows the operator of such a device to make targeted adjustments certain process conditions and conditions in different areas of the reaction space 4.

For example, the vertical sections in cooperation with adjustable slats 10, 10a, 10b allow the reaction space 4 to be subdivided into vertical zones of different fermentation, hygiene and / or drying states. These advantages of zoning with different ventilation adapted to the respective process state via the angles of attack of the lamellae 10, 10a, 10b come from a semi-continuous mode of operation, i.e. particularly against operation with partial emptying and refilling taking place at desired intervals. However, it also has advantages for discontinuous batch operation, where it is made possible by such a construction, through the head region of the reaction space 4, which can be free of filling material after the material has been filled in and deposited, in particular also during the microbiological degradation process Close the slats 10a of the top section largely to seal. This can prevent the supply air from flowing preferentially through this part of the reaction space due to the lower air resistance and deteriorating or completely stopping the reactor performance.

The dimensions of the lamellae 10, 10a, 10b are variable within wide limits. In practice, however, they are about 5 to about 30 cm wide and about 0.2 to about 0.8 cm thick for most applications. You can choose any length; For example, they can only have a length of 0.5 m or less in small systems, but can also have a length of 10 m and more in large systems. However, it is then necessary to support the slats one or more times over their length by load-bearing devices in order to prevent undesired deformation of the slats by e.g. Prevent bending or kinking.

A slat width of approximately 12 to approximately 15 cm with a slat thickness of 0.5 cm has proven particularly useful. The vertical spacing of the slats arranged one above the other in relation to points of the same position, for example from the upper edge to the upper edge, is approximately 5 to approximately 20 cm, a vertical distance of approximately 10 cm being particularly advantageous for constructional and procedural reasons, especially in connection with slats from about 12 to about 15 cm wide. In the case of embodiments without additional grilles or nets (see below) in the openings of the slat walls, it is important that the vertical slat distance, slat width and angle of attack are matched to one another so that at the selected angle of attack the upper edge of each slat is at least at the same height as the bottom edge of the next one, overlying slat, preferably even higher. In this way, a maximum of material retention in the reaction chamber 4 is achieved with optimal ventilation.

For most operating conditions in which an air flow is intended, the setting angles of the slats of approximately 40 to approximately 70 degrees, measured from the horizontal, lead to the desired success. However, for reasons of a special mode of operation, it may be advantageous to select the angles of attack within separately adjustable sections outside of these values, in order, for example, to intentionally bring about a reduced or increased air flow through such sections. It is clear to the person skilled in the art that microorganisms for recycling mixed substrates have different oxygen requirements depending on the biodegradability of the materials. This fact can be taken into account with a device according to the invention with adjustable slats in a relatively simple manner without changing the blower output or possibly having to use an additional, separate blower. If necessary, a compensating valve for excess supply air must be provided on the supply air side in order to lead a constant air flow through those zones of the reaction space where the fins have not been adjusted.

Grids or nets, which cover the openings between the slats 10, 10a, 10b, especially in the immovable version, are in principle not necessary, but give an additional measure of security, so that even with a very flat, i.e. wide opening angle of attack, for example 35 degrees or less, reliable material retention within the reaction space 4 remains guaranteed. Such grids or nets have a mesh size of approximately 0.2 to approximately 6 cm, preferably approximately 0.5 to approximately 3 cm, and consist of metal or a suitable, mechanically resilient plastic which is chemically resistant under the given conditions of use and temperatures of up to approximately 100 ° C endures undamaged and without degrading its mechanical properties.

In a further embodiment, vertical sections are also formed by adjustable horizontal elements 1 1 a, 1 1 b, in particular those which are tubular and rotatable about their longitudinal axis and extend over the entire or approximately the entire length of the reaction space. These are preferably elements of elliptical, triangular or polygonal cross section, which are arranged in one or more horizontal planes in such a way that they lie essentially parallel to one another and in at least one rotational position the reaction space in two or more superposed, preferably at least approximately closed , Divide sections. It is self-evident to the person skilled in the art that this effect can also be achieved by other embodiments of the horizontal elements, for example by horizontally arranged blind structures or slatted floors that can be displaced relative to one another (column width preferably at least 20 cm) and the like.

Such horizontal elements in the closed position 11b can, for example, hold back contents of a lower section, while twisting the horizontal elements of an overlying level into an opening position 11a creates an open connection between two previously separated sections, for example, filling material from an upper section in can penetrate an underlying one - if necessary, controlled and carefully metered. This makes it possible, for example, to compensate for the reduction in volume when the filled material is deposited and / or, if desired, to set up and / or maintain zones of different microbiological activities, hygienization and / or drying.

It is thus also possible, for example, for a lower section to go through a drying phase, while the sections above it are still being microbiologically degraded and hygienized. In interaction with adjustable slats, a sophisticated mode of operation of the device according to the invention can be achieved in this way. For geometric reasons, such tubular horizontal elements 1 1 a, 1 1 b are found in practice only in devices with straight lamella walls, i.e. with rectangular or square reaction spaces, use.

Depending on the type and nature of the filling material used, e.g. particulate, granular, fibrous, pasty, compact, loose etc., as well as the type of filling, e.g. tight filling with granules of different grain sizes or mixed filling with pasty material and loosening structural material such as Wood chips, chopped material, bark chips and the like, the layer thickness (= width) of the reaction space 4 can vary within relatively large ranges. In practice, layer thicknesses of approximately 50 to approximately 250 cm are usually usable, with a layer thickness of approximately 60 to approximately 120 cm being preferred, for example, for pasty filling material, in particular in larger systems, while, for example, material with lower density and at the same time higher Strength can successfully use layer thicknesses of up to 250 cm and more with the best process economy. Regardless of the process economy, the lower limit of the layer thickness of the reaction space 4 is also determined by the space requirement of the lamella walls and the internal fittings of the reaction space, and by a required minimum distance between the lamella walls for the purpose of mechanically filling the reaction space 4 by means of conventional filling devices.

While the device according to the invention, together with its facilities, can in principle be built in any size, in most cases a container 2 with lamella walls 3a, 3b of a maximum of about ten meters in height with a container width of about three to four meters is for a pair of lamella walls or about six to seven meters is sufficient for two couples. For the sewage sludge, organic residues and / or other organic waste from small and medium-sized polluters, in many cases even a container of only about three to four meters in height is sufficient. In the case of containers with reaction rooms that are less than one meter high, the cost-effectiveness limit is often already fallen short of, so that there are difficulties in marketing them, although this does not change their functionality.

It has also proven advantageous for fluidic reasons to expand the exhaust air space or - in the case of more than one exhaust air space - the exhaust air spaces towards the exhaust air duct in a funnel shape, which in the case of a version with two reaction spaces and centrifugal, i.e. from an internal one Supply air space directed outwards to the two exhaust air spaces, air flow is achieved through correspondingly inclined container walls. This prevents possible exhaust air build-up and thus also adequately ventilates the floor area of the reaction rooms. Otherwise, the exhaust air spaces must be dimensioned in such a way that an exhaust air backlog cannot occur with the expected air volumes.

In a preferred embodiment, the device according to the invention consists of a heat-insulated, rectangular or square bioreactor container 1 3 with two pairs of at least approximately plane-parallel lamella walls 14a, 14b, 14c, 14d, in particular those of the same size and geometry, i.e. with two reaction spaces 1 5a, 15b essentially rectangular horizontal cross section. In principle, however, design variants with three or more, preferably an even number, of such reaction spaces 15a, 15b are also feasible, although such systems have certain constructional and cost-related disadvantages.

Embodiments with one or more reaction spaces 30, 31 closed in a ring are likewise fundamentally producible, but have considerable constructional and / or procedural disadvantages. no matter whether triangular, polygonal or round cross-section. In such systems, the two air-permeable lamella walls 29a, 29b, 32a, 32b of each pair are arranged essentially concentrically one inside the other, preferably concentrically around an imaginary vertical longitudinal axis of the reactor vessel.

In the case of polygonal, annularly closed reaction spaces 30, 31, the structural disadvantages mainly relate to the effort involved in producing many short instead of a few long lamella walls and curved lamellae in the case of round or elliptical reaction spaces. Process engineering disadvantages arise, among other things, from the fact that the annularly closed shape of the lamella wall arrangement always results in a cross-sectional constriction in the centripetal direction, which can lead to the problems of the prior art mentioned at the outset. In addition, poorly ventilated or non-ventilated dead zones can arise in the region of the corners 33 of the polygonal, annularly closed embodiments, which is undesirable in any case.

In the preferred embodiment of the present invention with two pairs of plane-parallel lamella walls, a constant layer thickness of the two reaction spaces 15a, 15b is ensured without having to accept the disadvantage of a narrowing of the cross-section. It is fundamentally possible to lead the supply air inwards from the two outside air spaces 1 6a, 1 6b into an exhaust air space or vice versa. However, the centripetal air flow - i.e. from the outside inwards - has certain advantages, particularly with regard to the collection of warm exhaust air in the head space 1 7a of the exhaust air area 1 7 and with regard to the installation of a heat exchanger and / or condensate trap in the exhaust air area 1 7 .

In a likewise preferred embodiment, the container 13 tapers - primarily for receiving and discharging the finished material - below the inner, horizontal container bottom 19 in a funnel shape and opens into a closable outlet opening 21. Between the tank bottom 19 and the outlet opening 21 there is an air space 20 which is connected to at least one supply air line 22. The container bottom 1 9 is designed to be air-permeable in the area outside the exhaust air zone 1 7, that is to say in the area of the supply air and reaction spaces 1 5 a, 1 5 b above it, in particular in the form of a perforated bottom with perforated flaps 25 for emptying the container. The supply air is introduced into the space 20 below the tank bottom 19, forcibly flows through the holes in the perforated base and penetrates the reaction spaces 1 5a, 1 5b from below and through the supply air areas 1 6a, 1 6b. The inflow of below has the particular advantage that the organic material in the floor area, which often tends to clump together and is therefore poorly supplied with air, is adequately ventilated and loosened.

The device according to the invention also contains, preferably in each embodiment, at least one, preferably at least two closable openings, in particular flaps 25, in the container bottom 1 9 in the area of the reaction spaces 1 5a, 1 5b, which on the one hand withstand the contact pressure caused by the filling material and on the other hand one enable easy emptying of the bioreactor contents.

The device according to the present invention contains at least one supply air line 22 per supply air space and at least one exhaust air line 23 per exhaust air space, as well as fans, valves, flaps, etc. in an arrangement which makes it possible to either push or close the air flow through the reaction spaces between the lamella walls suck or both, ie to press on the supply air side and to suck on the exhaust air side. In many applications, a combination of suction and draft fans installed on the supply and extract air side, together with controllable valves, has proven to be the most suitable in order to be able to lead an even air flow through the reaction spaces.

In an advantageous embodiment, the supply air line 22 also contains a regulable and / or controllable connection 28 to the exhaust air line 23 and / or to at least one external air source. This is of great advantage in cases where, for example, a desired proportion of the moisture-laden exhaust air is to be recirculated via the supply air line, or where, for example, odor-contaminated external air, e.g. from stables to be deodorized. In this case, the device according to the invention also functions as a biofilter.

A particularly energy-saving embodiment of the device according to the invention also contains a heat exchanger (not shown in the figures) which transfers the waste heat from the exhaust air to the cooler supply air as quickly as possible. This combines two advantages at once: The moisture-laden, warm or hot air up to 80 ° C is cooled by the cooler supply air, the moisture condenses and is either discharged into an existing duct network or - if necessary - at least partially reused to humidify the supply air . The supply air is preheated and in this way supports the biological degradation processes, which preferably take place under meso- to thermophilic conditions, in particular up to about 80 ° C. Coordinated control of the blowers and valves in the supply and exhaust air lines normally forces flow through the reaction chambers towards the center of the tank. However, the direction of flow can be reversed if desired for certain applications.

The bioreactor is preferably filled from above via a conveying and distributing device which distributes the filling material evenly into the reaction space via tightly closable openings, in particular filler flaps 24.

In a further embodiment, the device according to the invention with cyclically closed lamella walls or reaction spaces contains a device for discharging fermented and / or dried material. In the simplest case, this is a mechanically working discharge scraper which, depending on the type of device according to the invention, is attached to the bottom of the container (not shown in the figures) and transports the treated material from the bottom of the container to the emptying opening.

Like most devices of this type, the device according to the invention also contains

Device for temperature, pH, humidity, CO2 and / or 02 probes, which are attached to various points in the reaction spaces and / or air spaces, and in addition to controllable devices such as transport and conveying devices, inlet and outlet valves, flaps, Blowers, etc. also at least one regulating and / or control unit which enables the operation of the system to run fully automatically. In particular, this also makes it possible, in interaction with the various controllable elements, to optimally adjust the intensity and speed of the fermentation and / or drying depending on the type of the filling material and, if necessary, to correct the ventilation and / or dehumidification or humidification to make.

The invention will be explained in more detail below using an example. It goes without saying that the example serves only for additional information and does not represent any restriction to a specific embodiment.

Example 1 ; Partial aerobic fermentation followed by drying

In the process described below, activated sludge from a municipal wastewater treatment plant is converted to organo-mineral fertilizer by rapid, aerobic partial fermentation and largely sterilized at temperatures up to 80 ° C (hygienized) and then in situ to a residual moisture content of less than 1 5 wt. % dried. This means that the product can be stored indefinitely, largely free of unpleasant odors and, in addition to the mineral content, still contains a valuable amount of organic compounds, particularly those that are more slowly degradable.

However, it is possible and envisaged that, depending on requirements, another end product can also be produced with the device according to the invention, for example a hygienized fertilizer or soil conditioner made of non-toxic, decayed sewage sludge. In the case of such products, the importance of the mineral component naturally outweighs the organic residual component. With the device according to the invention, however, it is also possible to treat water-containing residues with little or no or biologically unavailable organic content, i.e. at least sanitize and / or dry, for example for later disposal or incineration of industrial sludge or sewage sludge rich in heavy metals.

When other organic residues or wastes are treated, extensive aerobic degradation of the biologically available material is essentially achieved by extending the dwell time of the material in the bioreactor, together with a precisely coordinated ventilation. Depending on your wishes, you can achieve almost any degree of degradation of the material.

The organic material, in this case not digested municipal sewage sludge, is formed into strand-like granules by means of a press and transported via a conveyor belt to a distribution device which slowly moves back and forth over the two parallel reaction spaces 15a, 15b. The filling material is loosely passed through the opened filler flaps 24 of the bioreactor container 1 3 into the reaction spaces 15a, 15b with the support elements 27 and the support elements 26, in this case flat cylinders with a height of about 5 cm and a diameter of about 10 cm, suspended on cables. filled. In discontinuous operation, the entire container 1 3 of finished material from the previous batch was emptied beforehand, the elastically suspended ropes 27 being vibrated by means of a vibrating device to support the emptying. Small amounts of residual material that adhere to the lamellae 18 and the support elements 26 are in no way disturbing, but rather serve as a positive contribution as inoculation material to accelerate the start of the microbiological degradation in the subsequent batch.

The lamellae 18 of the lamella walls 14a, 14b, 14c, 14d, which form the two reaction spaces 15a, 15b, are set at an angle of 50 degrees (based on the horizontal) and thus effectively prevent that during the Filling material falls out of the reaction spaces or is pushed out. At this angle of attack, the upper edges of the slats were at the same height as the lower edges of the slats above them.

In the case of a semi-continuous mode of operation, only as much fresh filling material is always topped up in the upper region of the reaction spaces 1 5a, 1 5b as the fermented and dried material is drawn off via the flaps 25 on the bottom 1 9 and the bottom outlet opening 21. For this mode of operation - in addition to slats which can be distributed in sections - special devices are of great advantage or even necessary, such as horizontal elements 1 1 a, 1 1 b, which can largely close off an upper section of a reaction space from an underlying one by twisting or shifting it. Such a closing of the head space towards the bottom can, for example, prevent undesired cooling and / or dehumidification of the material underneath during the refilling process and at least considerably reduce undesirable air leakage with any unpleasant odors.

As soon as the filling process is complete, the microbiological phase begins. The slides and flaps 24, 25 in the container lid and bottom are closed. The filling material lies loosely in the reaction spaces 1 5a, 1 5b between the lamella walls 14a, 14b or 14c, 14d and the support elements 26. A certain amount of supply air is now blown in via a supply air space 20 below the tank bottom 19 by means of a blower installed on the supply air side through the perforation of the container bottom 19 and the flaps 25 and - supported by an extractor fan installed on the exhaust side - both from below and from the side via the fins 18 into the reaction spaces 15a, 15b, through the loose bed of organic material and sucked further into the exhaust air space 1 7. The air flow takes over the oxygen supply of the microorganisms and transports heat, CO2 and moisture through the fins 18 in the direction of the exhaust air space 1 7. This mixture of used air and water vapor is sucked off via a pipe 23. It has proven to be advantageous to subsequently pass the exhaust air through a peat filter for further deodorization, in which microorganisms are also located, and then, if appropriate, into a chimney. If necessary, however, at least a partial flow of this exhaust air can be recirculated into the supply air flow in order to optimally adjust the humidity and temperature conditions.

The microorganisms break down the various organic substances, primarily sugar, fatty acids and protein compounds, into CO2 and residues, creating heat. This heat drives the moisture to the surface of the filling material, from where it is blown away by the air is taken and cooled on a heat exchanger in the central exhaust air area 1 7 of the container 1 3 (not shown) by the colder, for example arriving at about 20-25 ° C, largely condensed and removed. Since normally only very small amounts of impurities such as ammonia can be found in the condensate, the condensate, which has a pH value of around 7.8 to 8, can be easily discharged into the sewage system. The remaining air-water vapor mixture goes into the chimney as previously described.

The amount of air required is determined on the basis of the measured values of some temperature, CO2 and moisture probes in the interior of the reactor and controlled via a controllable compensating valve in the supply air line 22 and, if appropriate, by changing the fan power and / or adjusting the angle of attack of the fins 18. Depending on the type of filling material, the process can also be supported and / or extended by at least partially recirculating the still moist or already condensed exhaust air via the connecting line 28.

The waste heat produced by the microorganisms continuously increases the temperature of the filling material and the air flowing through it slowly warms up to 80 ° C. This increases the absorption capacity for water vapor, which can be used to advantage in a subsequent drying phase. If, due to a too low proportion of usable organic matter, the self-heating by the microorganisms alone is not sufficient to reach and maintain the hygienisation temperature of around 70 to 80 ° C, the supply air may have to be additionally heated, despite preheating by a heat exchanger installed on the exhaust air side become.

As soon as the biodegradation process comes to an end, the temperature in the reaction space begins to drop. Depending on the type of filling, the microbiological phase, ie the partial fermentation, can be completed after a few, for example 10 to 15 hours, or only after a few days. In the subsequent drying process, which essentially follows the decaying biological phase, drying air is sucked through the treated product by means of a suction-pull blower. For this purpose, either fresh air is used or external air, such as, for example, odor-laden waste air from a digester, a production hall or an animal stall, is mixed in in any ratio or used entirely instead of fresh air. The organic odorous substances in the outside air are removed by the biofilter effect of the microorganisms in the reaction spaces 15a, 15b and the outside air is deodorized in this way. After a drying phase of approx. 5 to 10 hours in most cases, the treated, fermented and hygienized filling in this case reaches a final moisture content of less than 15% and is therefore indefinitely stable. As soon as the desired final humidity is reached, the heating of the supply air is switched off and a cooling phase of around one hour is initiated. For this purpose, unheated supply air is drawn through the reaction rooms and the contents are cooled to ambient temperature. The last blowers are then turned off, the lid and bottom flaps are opened, the container 13 is emptied with the support of the aforementioned vibrating device and a further quantity of fresh contents is poured into the reaction spaces 15a, 15b. The process can start again.

In the test facility, it was found that all of the unpleasant smelling components of the organic starting material had been converted and that the end product did not cause any unpleasant odors. The process described here was largely fully automated by means of a simple process control device and monitored by an equally simple process control system.

Claims

claims

1 . Device (1) for aerobic treatment, conditioning and / or drying of moist, preferably at least partially organic, material of essentially solid or pasty nature, based on

- A container (2, 13) with a divided interior, in which support elements (8a, 8b, 8c, 8d, 26) are arranged, the interior being divided by at least one pair of air-permeable walls in such a way that the mutually facing sides of the walls ( Inside) of such a pair a reaction space (4, 1 5a, 1 5b,

30, 31) form, while the sides facing away from one another (outer sides) form at least one supply air space (5, 1 6a, 1 6b) and at least one exhaust air space (6, 1 7), and

further additional devices, in particular transport and conveying devices, filling and emptying devices, air lines,

Blowers, valves, flaps, sliders, control and regulating devices, characterized in that a) the walls essentially consist of a louver-like lamella construction (3a, 3b, 14a, 14b, 14c, 14d, 29a, 29b, 32a, 32b), in which the slats (10, 10a, 10b, 1 8) in predetermined

Angle of attack, distances, lengths and / or widths are arranged, and b) the support elements (8a, 8b, 8c, 8d, 26) are spatially distributed within the reaction space (4, 1 5a, 1 5b, 30, 31) and thus arranged offset are that they are a diminution of the moisture-laden

Effect material pressure and thus enable a loosened bed.

2. Device according to claim 1, characterized in that the air-permeable walls (3a, 3b, 14a, 14b, 14c, 14d, 29a, 29b, 32a, 32b) have a height of approximately 1 to approximately 10 m, preferably approximately 4 to have about 6m, and the distance between the walls of a couple is about 50 to about 250 cm, in particular about 60 to about 1 20 cm.

3. Device according to one or more of the preceding claims, characterized in that the slats (10, 10a, 10b, 1 8) with their lower edges to the reaction space (4, 1 5a, 1 5b, 30, 31) and with their Point lower edges towards the reaction space (4, 15a, 15b, 30, 31) and with their upper edges away from the reaction space, a length of about 0.5 to about 10 m, a width of about 5 to about 30 cm and a thickness of about 0.2 to have about 0.8 cm and are preferably arranged at an angle of attack of about 40 to about 70 degrees, in particular 50 degrees, based on the horizontal.

4. Device according to one or more of the preceding claims, characterized in that the lamellae (10, 10a, 1 0b, 18) are arranged one above the other at a vertical distance of approximately 5 to approximately 20 cm, preferably approximately 10 cm, in such a way that the upper edge of each slat is at least at the same height as the lower edge of the slat immediately above it.

5. The device according to one or more of the preceding claims, characterized in that the slats (1 0, 1 0a, 10b, 1 8) are adjustable in their angles of attack.

6. The device according to one or more of the preceding claims, characterized in that the lamella construction (3a, 3b, 14a, 14b, 14c, 14d, 29a, 29b, 32a, 32b) in the vertical and / or horizontal direction at least two, preferably three to ten, contains sections that can be changed jointly and / or independently of one another with respect to the angle of attack of the slats.

7. The device according to one or more of the preceding claims, characterized in that between the slats (1 0, 10a, 1 0b, 1 8) additionally grids or nets with a mesh size of about 0.2 to about 6 cm, preferably from about 0.5 to about 3 cm.

8. The device according to one or more of the preceding claims, characterized in that the support elements (8a, 8b, 8c, 8d, 26) occupy approximately 0.5 to a maximum of approximately 10%, preferably approximately 1 to approximately 6%, of the container volume.

9. The device according to one or more of claims 1 to 7, characterized in that at least part of the support elements (8a, 8b, 8c, 8d, 26) is mounted on carrier elements (9, 27) and together with these takes up about 0.5 to a maximum of about 10%, preferably about 1 to about 6%, of the container volume.

10. The device according to claim 9, characterized in that the carrier elements (9, 27) ropes, rods or chains and the support elements (8a, 8b, 8c, 8d, 26) symmetrically or asymmetrically shaped bodies, in particular cubes, cylinders, cones, Plates, plates, balls and / or spiral elements are.

1 1. Device according to one or more of claims 1 to 8, characterized in that at least some of the support elements (8a, 8b, 8c, 8d, 26) are designed in the form of vertically arranged spirals or screws (8b), optionally with a partially interrupted spiral path .

1 2. Device according to one or more of claims 1 to 8, characterized in that at least part of the support elements (8a, 8b, 8c, 8d, 26) is designed as a blind-like slat construction (8d), preferably with adjustable slats, wherein this lamella construction (8d) consists of at least one, preferably two to fifteen, louver-like lamellar walls, which preferably extend in the vertical direction at least over three quarters of the height of the reaction space and optionally contain sections which together and / or independently of one another with respect to the angle of attack the slats are changeable.

1 3. Device according to one of claims 1 to 10, characterized in that the support elements (8a, 8b, 8c, 8d, 26) have a horizontal extent of about 5 to about 35 cm, preferably from about 10 to about 20 cm, have, are arranged at a vertical distance of about 10 to about 100 cm, in particular about 20 to about 50 cm and preferably at a side distance of about 20 to about 80 cm, in particular about 30 to about 50 cm.

14. The apparatus according to claim 1 3, characterized in that the spirals or screws (8b) has a spiral path of about 5 to about 35 cm Width, a diameter of about 10 to about 80 cm and preferably a pitch of about 10 to about 100 cm.

1 5. Device according to one or more of the preceding claims, characterized in that the interior of the container (2, 13) by at least one pair, preferably an even number of pairs, of straight air-permeable walls (3a, 3b, 14a, 14b, 14c , 14d), preferably of the same size and geometry, is subdivided and the reaction spaces (4, 15a, 15b) have a substantially rectangular horizontal cross section.

1 6. Device according to claim 1 5, characterized in that it contains rotatable or displaceable horizontal elements (1 1 a, 1 1 b) within the reaction spaces, the reaction space in at least one rotational or displacement position in two or more superimposed, preferably at least divide approximately closed sections.

1 7. Device according to claim 16, characterized in that the horizontal elements (1 1 a, 1 1 b) are tubular elements elliptical, triangular or polygonal cross-section and are arranged in one or more horizontal planes so that they are essentially parallel to each other are rotatable about their longitudinal axis and extend over the entire or approximately the entire length of a reaction space (4, 15a, 1 5b).

18. The device according to one or more of the preceding claims, characterized in that the container (2, 1 3) below the container base (1 9) contains a, preferably funnel-shaped, air space (20) into which at least one supply air line (22 ) opens, and that the container bottom (19) in the area outside the at least one exhaust air space (6, 1 7) is air-permeable.

1 9. Device according to one or more of the preceding claims, characterized in that the container bottom (1 9) in the region of the at least one reaction space (4, 15a, 15b, 30, 31) at least one closable opening, preferably at least one flap (25 ), having.

20. The device according to one or more of claims 9 to 19, characterized in that the support elements (8a, 8b, 8c, 8d, 26) and / or support elements (9, 27) are arranged movably and optionally connected to a vibration device.

21. Device according to one or more of the preceding claims, characterized in that the container (2, 13) is equipped with at least one supply air line (22) and at least one exhaust air line (23), at least one of which is connected to a heat exchanger, the supply air line (22) preferably also has an adjustable and / or controllable connection (28) to the exhaust air line (23) and / or to a source of external air.

22. The device according to one or more of claims 1 to 1 4, characterized in that the air-permeable walls (29a, 29b, 32a, 32b) of each pair are closed in a ring shape and arranged essentially concentrically one inside the other and a horizontal cross section of triangular, polygonal or round Have shape, where the pairs are arranged concentrically around an imaginary vertical longitudinal axis of the container.

23. A method for the aerobic treatment, conditioning and / or drying of moist, preferably at least partially organic, material of essentially solid or pasty nature, using a device according to one of the preceding claims, characterized in that the ventilation of the reaction spaces ( 4, 15a, 1 5b, 30, 31) by changing the blower output and / or adjusting valves in the supply and exhaust air lines (22, 23) and / or by adjusting the angle of attack of the slats (10, 10a, 1 0b, 1 8) is controlled.

24. The method according to claim 23 with a device according to one of claims 8 to 22, characterized in that the angle of attack of the slats (10, 10a, 10b, 1 8) is set differently in sections.

25. The method according to claim 23 or 24 with a device according to one of claims 1 6 to 22 with in at least two levels Arranged horizontal elements (1 1 a, 1 1 b), characterized in that by rotating or shifting the horizontal elements of one level, two sections of a reaction space (4, 1 5a, 1 5b) lying one above the other connect with one another, while the horizontal elements of the second level keep the subsequent sections separate.

26. The method according to one or more of claims 23 to 25, characterized in that by moving the slats (10, 10a, 10b, 1 8), support elements (8a, 8b, 8c, 8d, 26) and / or support elements (9 , 27) Material bridges that have formed between adjacent support elements are broken, thereby a further transport of the treated material within the device and / or a discharge of the same from the device is supported.