CONTAINER AND BIOGAS INSTALLATION

Abstract

So as to specify a container (2), in particular for generating biogas, comprising a preferably cylindrical main portion (3) and a base portion (9) arranged below the main portion (3), and a biogas system, which are of a simple, cost-effective construction that makes simple maintenance possible and which, with low energy consumption, effectively prevent blockages and funnel formation, it is proposed for the base portion (9) to have an annularly closed circulation duct (18).

Claims

1. A container for generating biogas comprising: a cylindrical main portion; a base portion arranged below the cylindrical main portion, characterised in that the base portion has an annularly closed circulation duct; the circulation duct having an inlet opening having an inlet cross section so as to admit medium into the circulation duct substantially tangentially to a vertical axis of the container, the circulation duct having an outlet opening having an outlet cross section so as to discharge medium from the circulation duct substantially tangentially to the vertical axis of the container; and a bypass line for connecting the outlet opening to the inlet opening, wherein the bypass line comprises a cross section that is variable.

2. The container according to claim 1, characterised in that the base portion has a substantially planar central region which is horizontally delimited by the circulation duct.

3. The container according to claim 1, further comprising an inlet pump for admitting medium into the circulation duct via the inlet opening and/or an outlet pump for discharging medium from the circulation duct via the outlet opening.

4. The container according to claim 1, characterised in that the outlet cross section is configured larger than the inlet cross section.

5. The container according to claim 1, characterised in that the circulation duct is made from a plastics material and cast together with a central region.

6. The container according to claim 1, characterised in that a tapered portion, which is shaped conically towards the base portion, is connected to the base portion in a direction of the vertical axis of the container.

7. The container according to claim 6, characterised in that the tapered portion has plastics material walls.

8. The container according to claim 6, wherein, the tapered portion is introduced in ground in a film-lined earth basin.

9. The container according to claim 1, further comprising a stirring system for stirring medium located in the container.

10. The container, according to claim 9, wherein the stirring system comprises a lower opening, an upper opening and a pipeline.

11. The container, according to claim 1, wherein the base portion is introduced in ground on top of a gravel bed.

12. A container for generating biogas comprising: a cylindrical main portion; a base portion arranged below the cylindrical main portion, characterised in that the base portion has an annularly closed circulation duct; the circulation duct having an inlet opening having an inlet cross section so as to admit medium into the circulation duct substantially tangentially to a vertical axis of the container, the circulation duct having an outlet opening having an outlet cross section so as to discharge medium from the circulation duct substantially tangentially to the vertical axis of the container; and a stirring system for stirring medium located in the container.

13. The container according to claim 12, further comprising a bypass line for connecting the outlet opening to the inlet opening, wherein the bypass line comprises a cross section that is variable.

14. The container according to claim 12, characterised in that the base portion has a substantially planar central region which is horizontally delimited by the circulation duct.

15. The container according to claim 12, further comprising an inlet pump for admitting medium into the circulation duct via the inlet opening and/or an outlet pump for discharging medium from the circulation duct via the outlet opening.

16. The container, according to claim 12, wherein the stirring system comprises a lower opening, an upper opening and a pipeline.

17. A container for generating biogas comprising: a cylindrical main portion; a base portion arranged below the cylindrical main portion, characterised in that the base portion has an annularly closed circulation duct; the circulation duct having an inlet opening having an inlet cross section so as to admit medium into the circulation duct substantially tangentially to a vertical axis of the container, the circulation duct having an outlet opening having an outlet cross section so as to discharge medium from the circulation duct substantially tangentially to the vertical axis of the container; and an inlet pump for admitting medium into the circulation duct via the inlet opening and/or an outlet pump for discharging medium from the circulation duct via the outlet opening.

18. The container according to claim 17, comprising a stirring system for stirring medium located in the container, wherein the stirring system comprises a lower opening, an upper opening and a pipeline.

19. The container according to claim 17, characterised in that a tapered portion, which is shaped conically towards the base portion, is connected to the base portion in a direction of the vertical axis of the container.

20. The container according to claim 17, characterised in that the outlet cross section is configured larger than the inlet cross section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In the drawings, in detail:

[0027] FIG. 1 is a vertical section through a biogas system according to the invention in a preferred embodiment comprising a container according to the invention in a preferred embodiment;

[0028] FIG. 2 is a detailed view of the region II of FIG. 1, showing the base region of the biogas system of FIG. 1;

[0029] FIG. 3 is a schematic plan view of a preferred embodiment of a base portion of a container according to the invention.

DETAILED DESCRIPTION

[0030] FIG. 1 is a vertical sectional view of a preferred embodiment of a biogas system 1 according to the invention comprising a container 2 in an embodiment of the invention. As can be seen in FIG. 1, the container 2 has a cylindrical main portion 3, to which a conically tapering portion 4 is connected downwards. The cylindrical main portion 3 has a wall 5 of reinforced concrete. The wall 5 is formed on an annular plinth foundation 6.

[0031] The conically tapered portion 4 is located in the ground 7 in the manner of a lagoon. The tapered portion 4 is made from PE-HD. The wall of the tapered portion 4 is at an angle 8 of 10-45, preferably 30, to the horizontal.

[0032] The tapered portion 4 is terminated downwards by a base portion 9. The base portion 9 substantially consists of a reinforced concrete base plate 10. The base plate 10 is mounted on a gravel bed 11 provided in the ground 7 in the region of the base plate 10, so as to pump out groundwater if required.

[0033] In the embodiment presently being described, the diameter of the cylindrical main portion 3 is approximately 24 m, whilst the diameter of the base plate 10 according to the example is approximately 5 m. The conically tapered portion 4 therefore has a vertical extent of approximately 6 m, depending on the angle 8.

[0034] The wall 5 of the main portion 3 of the container 2 according to the invention is provided with a stirring system 12. The stirring system 12 substantially consists of a lower opening 13 in the wall 5 and an upper opening 14 in the wall 5 as well as a pipeline 15 connecting the lower opening 13 to the upper opening 14. A pump is arranged in the pipeline 15 so as to withdraw medium 16, stored in the cylindrical main portion 3 of the container 2, from the lower opening 13 and recirculate it into the container 2 via the upper opening 14. In this way, a revolution can be generated in such a way that nutrients contained in the media 16 are supplied to the active bacteria as uniformly as possible. Hereinafter, the base portion 9 of the container 2 of the biogas system 1 of FIG. 1 is explained in greater detail with reference to FIGS. 2 and 3. In this connection, FIG. 2 is an enlargement of the detail II of FIG. 1. As can be seen in FIG. 2, the reinforced concrete base plate 10 has a substantially planar central region 17. The planar central region 17 is annularly enclosed by an annular duct 18. The annular duct 18 consists of polyethylene plates 19, which are cast together with the reinforced concrete base plate 10. The base 20 of the annular duct 18 is below the planar central region 17 of the base plate 10.

[0035] In the transition between the planar central region 17 of the base plate 10 and the annular duct 18, there is an annular transition region 21 at an inclination to the horizontal. In the embodiment shown here, the inclined transition region 21 is lined with a polyethylene plate 22. The polyethylene plate 22 overhangs the vertical inner wall 23 of the annular duct 18 at the radially outer end 24, in the manner of a roof. Moreover, in the radially outer region, the base plate 10 has a further radially inwardly inclined region 25, which itself annularly encloses the annular duct 18. Like the inclined transition region 21, the inclined outer region 25 is lined with polyethylene plates 26, which protrude into the annular duct 18 in the manner of a roof.

[0036] FIG. 3 is a plan view of the base portion 9 viewed in the direction of the arrow III in FIG. 2. As can be seen particularly clearly in FIG. 3, the annular duct 18 has an inlet opening 27 and an outlet opening 28. A polyethylene inlet pipe 29 is passed through the inlet opening 27 in such a way that, when medium is supplied through the inlet pipe 29 in a tangential direction, an annular flow 30 is generated in an anticlockwise direction.

[0037] On the other side, an outlet pipe 31, through which medium can be withdrawn from the annular duct 18 in a tangential direction so as to generate or reinforce the annular flow 30, is passed through the outlet opening 28.

[0038] Returning again to FIG. 1, hereinafter the effect of the inlet pipe 29 and the outlet pipe 31 for generating the annular flow 30 in the annular duct 18 is explained in greater detail. As can be seen in FIG. 1, the outlet pipe 31 is connected to a pump 32, which communicates via a valve 33 with a storage container 34 (not shown in greater detail). It can further be seen that a bypass line 35, which closes together the outlet pipe 31 and the inlet pipe 29, is provided at the output of the pump 32. It can further be seen that a slider 36 (only schematically shown) is provided in the bypass line 35. By means of the slider 36, the ratio of the medium conveyed by the pump 32 and recirculated into the annular duct 18 through the inlet opening 27 via the bypass line 35 and the inlet pipe 29 to the proportion of medium passed into the storage container 34 can be set.

[0039] Incidentally, further components of the biogas system 1, for example for withdrawing the generated biogas, are not shown in greater detail in FIG. 1. These may be configured in a conventional manner well known to an appropriate person skilled in the art.

[0040] For operating the biogas system 1 comprising the container 2 of FIGS. 1 to 3 according to the invention, medium 16 is filled into the container 2 to a fill level 37 via an opening (not shown in FIG. 1). The medium 16 is biomass as a starting material for the biogas generation. Sludges having a high proportion of heavy material/sinking material, for example of sand or grit, are also conceivable as a medium 16. It is initially the stirring system 12, which ensures revolution of the medium 16 in the container 2, that ensures that the bacteria are supplied with organic nutrients and kept suspended, in particular for large diameters of the main portion 3, for example in the region of 10-40 m.

[0041] At the same time, however, according to the invention the annular flow 30 in the annular duct 18 in the base plate 10 serves to prevent encrusting and funnel formation in the base portion 9 of the container 2. For this purpose, by means of the pump 32, sludge is suctioned in the annular duct 18 via the outlet pipe 31 and the outlet opening 28, and can be supplied to a storage container via the valve 33. However, so as to maintain an annular flow 30 in the annular duct 18, part of the sludge suctioned via the outlet pipe 31 is recirculated into the annular duct 18 through the inlet opening 27 via the bypass line 35 and the inlet pipe 29. The ratio of this recirculation flow can be set by way of the slider 36 (not shown in greater detail) in the bypass line 35.

[0042] The slider 36 may be configured in any desired manner known to a person skilled in the art, for example as a control valve.

[0043] As a result of the annular flow 30 in the annular duct 18, prevention of depositions of sinking materials in the base portion 9 of the container 2 is brought about with a comparatively low energy input. Therefore, revolution by way of the stirring system 12 in the cylindrical main portion 3 of the container 2 can be operated with comparatively low energy expenditure without problems occurring.

[0044] Because the conically tapered portion 4 comprising polyethylene walls is arranged between the cylindrical main portion 3 having a large diameter, for example 15 m or more, and the base portion 9, the base portion 9 has a much smaller diameter, for example 3 m, than the main portion 3.

[0045] As regards setting the proportion of medium recirculated through the inlet pipe 29 via the bypass line 35, according to the invention a presetting is provided in that the diameter of the inlet pipe 29 is selected smaller than the diameter of the outlet pipe 31. It has been found to be particularly favourable if the diameter of the inlet pipe 29 is 110 mm and the diameter of the outlet pipe 31 is approximately 200 mm.

[0046] In this way, a container and a biogas system are disclosed which can be operated with lower investment costs and lower operating costs than conventional systems and containers, without blockages and sedimentations occurring as a result of sinking materials.

LIST OF REFERENCE NUMERALS

[0047] 1 Biogas system [0048] 2 Container [0049] 3 Main portion [0050] 4 Conically tapered portion [0051] 5 Wall [0052] 6 Plinth foundation [0053] 7 Ground [0054] 8 Angle [0055] 9 Base portion [0056] 10 Base plate [0057] 11 Gravel bed [0058] 12 Stirring system [0059] 13 Lower opening [0060] 14 Upper opening [0061] 15 Pipeline [0062] 16 Medium [0063] 17 Planar central region [0064] 18 Annular duct [0065] 19 PE plates [0066] 20 Base [0067] 21 Inclined transition region [0068] 22 PE plate [0069] 23 Inner wall [0070] 24 Outer end [0071] 25 Inclined outer region [0072] 26 PE plate [0073] 27 Inlet opening [0074] 28 Outlet opening [0075] 29 Inlet pipe [0076] 30 Annular flow [0077] 31 Outlet pipe [0078] 32 Pump [0079] 33 Valve [0080] 34 Storage container [0081] 35 Bypass line [0082] 36 Slider [0083] 37 Fill level