DE102013006266A1 - Method and device for the aerobic microbiological heating of pourable moist organic solids - Google Patents

Abstract

The present invention relates to a method for the aerobic microbiological warming of pourable moist organic solids, preferably of partially dewatered manure, wherein the solid is moved in a conveying direction (8), wherein the solid along the conveying direction (8) alternately by mixing zones (10) and Resting zones (12) is moved, wherein in the mixing zones (10) an active mixing of the solid with mixing elements (11) to enter oxygen, in particular atmospheric oxygen, in the solid, and wherein in the quiet zones (12) no mixing or a weaker Mixing as in the mixing zone (10) takes place, so that the solid is in internal rest to allow the growth of microorganisms and thus the microbiological warming.

Description

The present invention relates to a method for the aerobic microbiological warming of pourable moist organic solids and a corresponding device. In particular, by means of the method according to the invention and the device according to the invention, partially dehydrated manure, preferably manure, is treated in order to obtain hygienized litter.

The state of the art, for example EP 1 817 532 , describes that cattle slurry with separators is partially dewatered and then sanitized in rotary drums. As a result, bedding can be recycled from manure. Corresponding regulations (for example, Regulation EC 1774/202 of the European Parliament) require the use of such a substance, a hygienization at 70 ° C and a residence time of 1 hour. The use of external heat sources is unacceptable for business reasons. A disadvantage of previously known solutions is that the solid to be introduced has to have a content of dry matter which must be continuously above 38% in order to achieve the required values of 70 ° C. over 1 hour. The upstream press screw separator comes mechanically to its limits. The variability of the manure supplied still requires special measures in the regulation of the entire process.

It is an object of the present invention to provide a method for the aerobic microbiological warming of free-flowing moist organic solids and a corresponding device, which enable cost-effective implementation or production of a safe and energy-efficient heating of the solid, in particular for sanitizing bedding. In particular, the method and apparatus for the thermophilic organisms in the solid must provide appropriate living conditions so that maximum utilization of high temperature production by these organisms becomes possible.

The object is achieved by the independent claims. The dependent claims each relate to advantageous embodiments of the invention.

Thus, the object is achieved by a method for aerobic microbiological warming pourable moist organic solids, preferably partially dehydrated manure. In particular, the method produces litter for cattle, preferably for dairy cattle, from the resulting manure. In the process, the solid is moved in a conveying direction. During this movement, the solid passes alternately along the conveying direction mixing zones and resting zones. In the mixing zones an active mixing of the solid with mixing elements takes place. In this mixing takes place an entry of oxygen in the solid. In particular, air is introduced so that an enrichment takes place with the atmospheric oxygen. In the quiet zones, the solid is in inner peace. As a result, the aerobic organisms can grow in the quiet zones, which simultaneously sets the microbiological warming. Since an active mixing and thus an input of oxygen takes place before the quiet zones, the aerobic organisms in the resting zones have sufficient oxygen for the multiplication and thus for the microbiological warming. In the quiet zones there is no mixing or at least a weaker mixing than in the mixing zones. Advantageously, the solid is moved in a continuous process along the conveying direction. As a result, a movement of the solid takes place in the quiet zones. This can lead to a minimal mixing. Advantageously, however, the solid is in the quiet zones as far as possible in an internal rest and moves only relative to its environment.

In the context of the invention, it was recognized that the high temperature of at least 70 ° C over a longer period of time can be achieved, in particular, if optimal living conditions for archaea are created. These organisms even multiply at a temperature of, for example, 110 ° C. In particular, the method according to the invention and also the device according to the invention represent an optimal living condition for the multiplication of aerobic archaea. This is particularly important since aerobic organisms, which require oxygen for their metabolism, have a much faster propagation rate and thus also a higher performance in the Temperature generation have as anaerobic organisms. In particular, the method of the invention promotes the growth of halophilic archaea, which are mostly aerobic-chemoorganotrophic and gain their energy from chemical reactions of organic compounds.

According to the invention, an entry of atmospheric oxygen into the solid takes place in the mixing zones. In each subsequent to the mixing zones quiet zones there is a growth of microorganisms and thus the desired microbiological warming.

It is preferably provided that the solid is moved in the rest zones and / or in the mixing zones in the conveying direction. In particular, there is a continuous conveying of the solid, so that in the Quiet zones and in the mixing zones the movement takes place. The quiet zones are designed so that the solid moves in the first place relative to its environment, but it is mixed as little as possible.

Moreover, it is preferably provided that along the conveying direction at least two mixing zones and two quiet zones are provided alternately one after the other. Particularly preferably, there are at least three mixing zones and correspondingly three resting zones, which alternate in each case.

Furthermore, it is preferably provided that the solid lingers longer in the quiet zones than in the mixing zones. In a continuous promotion of the solid one will preferably form the mixing zones shorter than the quiet zones, so as to achieve the longer residence time.

The movement of the solid is preferably carried out in a container. The container is preferably designed as a drum. The mixing zones and quiet zones are arranged in the container.

Furthermore, it is preferably provided that the movement of the solid in the conveying direction and at the same time also the mixing of the solid in the mixing zones takes place by a rotation of the container. In this case, a drum is preferably used, the drum longitudinal axis is aligned horizontally.

The invention further includes an apparatus for the aerobic microbiological heating of pourable moist organic substances. In this case, preferably partially dewatered manure is treated to obtain hygienized litter. The device comprises a container in which the solid is movable in the conveying direction. In the container, the mixing zones and resting zones are formed alternately successively. In each case at least one mixing element for active mixing of the solid is located in the mixing zones. The quiet zones are designed so that no or only a very small mixing of the solid takes place.

The subclaims and the advantageous embodiments of the method according to the invention find correspondingly advantageous application for the device according to the invention. Accordingly, the subclaims and advantageous embodiments, as described in the context of the device according to the invention, find advantageous application for the method according to the invention.

In particular, it is provided that the mixing elements are firmly connected to the container, wherein the container, in particular as a drum, is rotatable. As a result, the mixing elements rotate with the container. Alternatively, it is possible that the mixing elements are rotatable relative to the container. The rotation of the mixing elements allows on the one hand the mixing of the solid and on the other hand at the same time a promotion of the solid in the conveying direction. This is achieved in that the mixing elements exert a pressure on the solid in the conveying direction and thus move the solid in the conveying direction.

For this purpose, the mixing elements are bent in particular like a propeller about their own element longitudinal axis. The mixing elements are particularly preferably metal sheets which are twisted or bent around their own longitudinal axis. Each time the container is rotated, the solids are raised slightly on the respective upward side of the respective mixing element, while in the lower region, a depression occurs, into which the solids raised above are introduced and mixed with the air flowing through them. Due to the propeller-like design of the mixing elements, a pressure and, on the other hand, a pressure release is exerted on the solids quantities lying between the mixing elements with each rotation on the lower side in the conveying direction. This causes the solid under its own weight to move a little from the feed side to the discharge side without any internal movement and, in total, every rotation. Between the mixing elements, ie in the quiet zones, the microorganisms have enough time to grow through the amount of solids.

The container is preferably formed as a drum. The drum has a drum longitudinal axis. This corresponds to the conveying direction. At least one of the mixing elements extends across the drum. Preferably, the at least one mixing element extends perpendicular to the drum longitudinal axis.

In particular, it is provided that at least one of the mixing elements is attached with its two ends to a lateral surface of the drum and is spaced between the two ends of the lateral surface. In this case, the mixing element preferably cuts the drum longitudinal axis. The mixing elements are thus designed as a propeller, with the axis of rotation of the propeller sitting coaxially on the drum longitudinal axis.

Furthermore, it has been found to be advantageous in the context of the invention that the archaea have locomotor organs, so-called flagella. These locomotion organs sit laterally on the archaea and favor a narrowing of the archaea between gaps in the solid. The Rate of movement of thermophilic microorganisms is reported to be between 400 to 500 bps (bodies per second). At a size of 1 .mu.m per thermophilic organism results in liquid, a speed of movement of 1.44 to 1.8 m per hour. The speed of movement in solid is estimated within the scope of the invention to about 0.5 m. Accordingly, taking into account the conveying speed of the solid, a dimensioning and a spacing of the individual mixing zones and quiet zones. A mixing zone length of the individual mixing zone and a resting zone length of the individual rest zone are defined in the conveying direction, in particular along the drum longitudinal axis. The single quiet zone length is preferably at least 2 times, preferably at least 2.5 times, particularly preferably at least 3 times, the mixing zone length. The total length of the drum is for example 10 m. Depending on the filling on the feed side and the overflow on the discharge side, for example, the speed of the solid in the drum is 1 m per hour. The resting zone length is preferably set at 1 m, so that at a growth rate of the organisms of about 0.5 m per hour, the solid will grow through sufficiently from both sides. Accordingly, seven mixing zones each having a mixing element are arranged in the drum.

As a result, the microorganisms have sufficient time to gain from the implementation of organic compounds a corresponding amount of energy for the required increase in temperature can. As a result, a higher water evaporation is achieved. The content of dry matter in the solid to be introduced can thus be effectively reduced. Accordingly, an upstream press screw separator is less loaded.

Hereinafter, an embodiment of the invention will be described in detail with reference to the accompanying drawings. Showing:

1 a partially cutaway, isometric view of a device according to the invention according to an embodiment, and

2 a partially cutaway side view of the device according to the invention according to the embodiment.

The 1 and 2 show an embodiment of a device 1 for the aerobic microbiological warming of pourable moist organic solids. By means of this device 1 the process according to the invention is carried out. 1 shows an isometric, partially cutaway view. 2 shows a side view of the device 1 , also partially cut.

The device 1 includes a container 2 , designed as a drum. The container 2 includes a lateral surface 3 with two end faces 4 , The container 2 extends along a drum longitudinal axis 7 , At one end 4 is an entry page 5 educated. At the other end 4 is a discharge page 6 educated. The container 2 becomes the drum longitudinal axis 7 according to the marked direction of rotation 9 turned.

At the entry page 5 the solid to be treated is added to the container 2 entered. Along a conveying direction 8th the solid becomes in the container 2 to the discharge page 6 promoted. The drum longitudinal axis 7 is arranged in particular horizontally.

2 shows the division of the container 2 in several mixing zones 10 and relaxation areas 12 , Along the drum longitudinal axis 7 are alternately the mixing zones 10 and the quiet zones 12 arranged. At the entry page 5 there is an entry zone 13 , At the discharge side 6 there is a discharge zone 14 ,

In every mixing zone 10 is a mixing element 11 intended. The mixing element 11 can also be referred to as a guide or baffle. The respective mixing element 11 extends from one end 17 to the other end 17 along an element's longitudinal axis 18 , With the two ends 17 is the respective mixing element 11 on the lateral surface 3 of the container 2 attached. Accordingly, the mixing elements rotate 11 with the container 2 around the drum longitudinal axis 7 ,

The element longitudinal axis 18 , in particular the middle of the mixing elements 11 , cuts the drum longitudinal axis 7 , The mixing elements 11 thus extend across the container formed as a drum 2 ,

Each in two adjacent mixing zones 10 are the mixing elements 11 arranged offset by 90 ° to each other. Furthermore, the individual mixing elements 11 propeller-like around their own elemental longitudinal axis 18 twisted.

The mixing elements 11 ensure a thorough mixing of the solid in the mixing zones 10 in the radial direction, ie perpendicular to the drum longitudinal axis 7 , By the propeller-like rotation of the mixing elements 11 around its element's longitudinal axis 18 , the rotating mixing elements can 11 a pressure on the solid in the conveying direction 8th exercise. As a result, the solid moves continuously from the entry side 5 to the discharge page 6 , Furthermore ensures that through the mixing elements 11 applied pressure for a corresponding relative movement of the compact mass of the solid in the quiet zones 12 ,

2 shows a mixing zone length 15 and a quiet zone length 16 , The quiet zone length 16 is designed much longer than the mixing zone length 15 , so in the quiet areas 12 the microorganisms have sufficient time to grow in the solid.

As the embodiment shows, there are several mixing zones 10 arranged. In each case between two mixing zones 10 there is a rest area 12 , Between the one end wall 4 and the first mixing zone 10 is the entry zone 13 educated. Between the last mixing zone 10 and the other end wall 4 is the discharge zone 14 , The quiet zones 12 are designed so that as little as possible mixing of the solid takes place in this area. By the constant rotation of the container 2 the solid is in the quiet zones 12 only very slightly mixed.

The exact mixing zone lengths 15 and quiet zone lengths 16 as well as the number of mixing zones 10 and relaxation areas 12 is chosen according to the growth rate of the microorganisms.

LIST OF REFERENCE NUMBERS

1

contraption

2

container

3

lateral surface

4

front sides

5

entry page

6

order page

7

drum longitudinal axis

8th

conveying direction

9

direction of rotation

10

mixing zone

11

mixing element

12

rest areas

13

entry zone

14

discharge zone

15

Mixing zone length

16

Quiet zone length

17

end up

18

elements longitudinal axis

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1817532 [0002]

Claims (13)

Method for the aerobic microbiological warming of free-flowing moist organic solids, preferably of partially dewatered manure, wherein a movement of the solid in a conveying direction ( 8th ), - wherein the solid along the conveying direction ( 8th ) alternately through mixing zones ( 10 ) and relaxation areas ( 12 ), wherein - in the mixing zones ( 10 ) an active mixing of the solid with mixing elements ( 11 ) is carried out to introduce oxygen, in particular atmospheric oxygen, into the solid, and - wherein in the rest zones ( 12 ) no mixing or weaker mixing than in the mixing zone ( 10 ), so that the solid is at rest to allow microbiological warming. A method according to claim 1, characterized in that the solid in the rest zones ( 12 ) and / or in the mixing zones ( 10 ) in the conveying direction ( 8th ) is moved. Method according to one of the preceding claims, characterized in that along the conveying direction ( 8th ) at least two mixing zones ( 10 ) and two quiet zones ( 12 ), preferably at least three mixing zones ( 10 ) and three quiet zones ( 12 ), more preferably at least four mixing zones ( 10 ) and four quiet zones ( 12 ), are provided alternately one after the other. Method according to one of the preceding claims, characterized in that the solid in the rest zones ( 12 ) lingers longer than in the mixing zones ( 10 ). Method according to one of the preceding claims, characterized in that the movement of the solid in a container ( 2 ), preferably in a drum, wherein the mixing zones ( 10 ) and relaxation areas ( 12 ) in the container ( 2 ) are formed. A method according to claim 5, characterized in that by rotating the container ( 2 ) simultaneously moving the solid in the conveying direction ( 8th ) and the mixing takes place. Contraption ( 1 ) for the aerobic microbiological warming of pourable moist organic solids, preferably partially dewatered manure, comprising - a container ( 2 ), in which the solid in a conveying direction ( 8th ) is movable, - in the container ( 2 ) formed mixing zones ( 10 ) each having at least one mixing element ( 11 ) for active mixing of the solid, and - in the container ( 2 ) trained relaxation areas ( 12 ), through which the solid in the conveying direction ( 8th ) is movable without mixing the solid or with a weaker mixing than in the mixing zones, - the mixing zones ( 10 ) and the quiet zones ( 12 ) in the conveying direction ( 8th ) are arranged alternately. Apparatus according to claim 7, characterized in that the mixing elements ( 11 ) in the container ( 2 ) or with the container ( 2 ) are rotatably arranged, and are adapted to the solid perpendicular to the conveying direction ( 8th ) and at the same time in the conveying direction ( 8th ) Apply pressure to the solid. Apparatus according to claim 8, characterized in that the mixing elements ( 11 ) propeller-like about its own longitudinal axis element ( 18 ) are bent in the conveying direction ( 8th ) Apply pressure to the solid. Device according to one of claims 7 to 9, characterized in that the container ( 2 ) is formed as a drum, wherein a drum longitudinal axis ( 7 ) of the conveying direction ( 8th ), and wherein at least one of the mixing elements ( 11 ) across the drum, preferably perpendicular to the drum longitudinal axis ( 7 ) extends. Apparatus according to claim 10, characterized in that at least one of the mixing elements ( 11 ) with its two ends ( 17 ) on a lateral surface ( 3 ) of the drum is fixed and between the two ends ( 17 ) from the lateral surface ( 3 ) is spaced. Device according to one of claims 10 or 11, characterized in that at least one of the mixing elements ( 11 ) the drum longitudinal axis ( 7 ) cuts. Device according to one of claims 7 to 12, characterized in that the mixing zones ( 10 ) in the conveying direction ( 8th ) a mixing zone length ( 15 ) and the quiet zones ( 12 ) a quiet zone length ( 16 ), wherein the quiet zone length ( 16 ) at least 2 times, preferably at least 2.5 times, particularly preferably at least 3 times, the mixing zone length ( 15 ) is.

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