WO2021111386A1

WO2021111386A1 - Fermentation plant

Info

Publication number: WO2021111386A1
Application number: PCT/IB2020/061499
Authority: WO
Inventors: Matteo Paolo MAZZERO; Nicola PADOAN
Original assignee: Ies Biogas S.R.L.
Priority date: 2019-12-06
Filing date: 2020-12-04
Publication date: 2021-06-10
Also published as: IT201900023283A1

Abstract

The present disclosure relates to a fermentation plant (100) comprising a fermentation tank (10) having an external wall (11) defining a fermentation environment (12) in said fermentation tank (10) in which said fermentation environment (12 ) is configured to contain a material to be fermented. The fermentation plant (100) further comprises an internal wall (15) configured to define an inspection compartment (20) in the fermentation tank (10). Such an internal wall (15) is interposed between the fermentation environment (12) and the inspection compartment (20). The fermentation plant (100) further comprises a stirrer (30) configured to stir the material to be fermented in said fermentation environment (12). The stirrer (30) comprises a shaft (31) rotatable around an axis of rotation (X), such a shaft (31) further comprises a first terminal zone (32) and a second terminal zone (33) opposite to said first terminal zone (32). The first terminal zone (32) is supported by said external wall (11) of the fermentation tank (10), while the second terminal zone (33) is supported by a supporting structure in said inspection compartment (20). The present disclosure also relates to a management method for managing a fermentation plant (100).

Description

FERMENTATION PLANT

DESCRIPTION

The present disclosure refers in general to a fermentation plant.

More specifically, the present disclosure refers to a fermentation plant for the production of biogas in which the maintenance activities are facilitated.

Traditionally, the known fermentation plants comprise a fermenter into which various natural substances are conveyed, including, for example, manure, slurry, poultry manure, vegetable waste and agricultural by-products.

The inside of the fermenter is kept at a controlled temperature and in the absence of oxygen so that bacteria can degrade the organic substance and produce biogas which will then be collected.

Some known fermentation plants comprise a fermentation tank, mainly with a circular section, and at least one stirrer for mixing the natural substances inserted inside the fermentation tank itself.

Two main classes of stirrers are known. A first class of stirrers comprises a support rod arranged vertically and an element rotating around a horizontal axis for moving the biomass inside the fermentation tank.

The other known stirrer, belonging to the class of so-called slow stirrers, comprises a rotation shaft arranged horizontally inside the fermentation tank. A plurality of blades are associated with said rotation shaft which extend radially from said rotation shaft for the movement and mixing of the biomass.

More specifically, a first terminal zone of the rotation shaft of such class of stirrers is associated with a wall of the fermentation tank, while the second terminal zone of said shaft is supported by a central supporting structure, that is to say arranged at the centre of the fermentation tank. It is thereby possible to arrange a plurality of stirrers belonging to the class of slow stirrers in the fermentation tank. Preferably, three slow stirrers are arranged at an angle of about 120° to each other.

Such a configuration of the known fermentation plants is often disadvantageous, especially if maintenance interventions are necessary inside the fermentation tank, especially in the area of the central supporting structure where the three slow stirrers radiate outwards.

In these cases, in the known plants, it is necessary to block the entire fermentation plant, empty the fermentation tank and repair the area of the end zone of the rotating shaft at the central supporting structure before the plant itself can resume operation.

It is therefore clear, also in the light of the general dimensions of fermentation plants and the amount of natural material contained in the fermentation tank, that such operations are complex and often of long duration. The interruption of the fermentation plant for long periods of time, also for simple ordinary maintenance interventions, considerably reduces the productivity of the plant, with consequent economic disadvantages.

The present disclosure aims to provide a fermentation plant which allows to overcome the aforementioned drawbacks with reference to the known art and/or to achieve further advantages.

This is achieved through a fermentation plant and a process as defined in the respective independent claims. Secondary features and particular embodiments of the object of the present disclosure are defined in the corresponding dependent claims.

In particular, the fermentation plant object of the present invention comprises a fermentation tank in turn comprising an external wall which defines a fermentation environment in the fermentation tank which is configured, in use, to contain a material to be fermented. The fermentation plant further comprises an internal wall configured to define an inspection compartment in said fermentation tank. In other words, the internal wall is interposed between the fermentation environment and the inspection compartment. The fermentation plant further comprises a stirrer configured to stir the material to be fermented in the fermentation environment. Said stirrer comprises a shaft rotatable around an axis of rotation, in which said shaft comprises a first and a second terminal zone, in which the second terminal zone is opposite to the first terminal zone. Specifically, the first terminal zone of the shaft is supported by the external wall of the fermentation tank, while the second terminal zone of the shaft is housed in said inspection compartment.

According to such an aspect, advantageously, the ordinary and extraordinary maintenance operations at the second terminal zone of the shafts of the stirrers can be performed from inside said inspection compartment. Thereby, it is not necessary to empty the natural material contained inside the fermentation tank. Consequently, the repair and maintenance operations are simplified and faster.

In particular, according to an aspect of the present disclosure, the internal wall comprises an opening configured to receive the second terminal zone of the stirrer shaft. In other words, the stirrer shaft is at least partially housed, or inserted, in an opening of the internal wall which defines the inspection compartment. Likewise, the external wall of the fermentation tank also comprises a second opening configured to receive the first terminal zone of the stirrer shaft.

According to a preferred aspect, the opening of the internal wall comprises a sealing gasket. It follows that, advantageously, the inspection compartment is fluidically isolated from the fermentation environment. Preferably, the second opening of the external wall also comprises a sealing gasket.

According to a further preferred aspect of the present disclosure, the fermentation plant further comprises a supporting structure which is configured to support the second terminal zone of the stirrer shaft. Such a supporting structure is arranged inside the inspection compartment. In other words, the supporting structure is arranged inside the internal wall of the fermentation plant. Consequently, the supporting structure is accessible from said inspection compartment, thus avoiding the need to empty the fermentation environment if maintenance activities are required at the second terminal zone of the stirrer shaft.

More particularly moreover, according to a further preferred aspect, the supporting structure comprises a bearing for each slow stirrer. More specifically, such a bearing is configured to support the second terminal zone of the shaft and to allow the rotation of the shaft itself. In other words, a bearing is arranged in the inspection compartment for supporting and rotating the stirrer shaft. Advantageously, therefore, maintenance operations at the bearing are facilitated, as such a bearing is accessible from the inspection compartment.

In general, therefore, the inspection compartment which houses the central supporting structure of the fermentation tank for supporting the slow stirrers, allows to overcome a major inconvenience for maintenance, inspection, or lubrication activities, in particular of the bearings, in the supporting portions of the rotation shafts of the slow stirrers.

In particular, the bearings may require periodic lubrication and are subject to damage or breakage.

In other words, the maintenance of the bearings of the central support of the stirrer shafts involves very long and complex operations which require the interruption of the operation of the plant and the emptying of the fermentation tank.

According to a further aspect, a second bearing for each slow stirrer is also arranged at the first terminal zone of the rotation shaft, i.e. , at the end arranged on the peripheral or external wall, or shell, of the fermentation tank. It follows that, advantageously, both bearings can be easily inspected, and that the maintenance operations of the bearings themselves are simplified. In fact, the second bearing can be inspected from the outside of the fermentation tank, while the second bearing can be inspected from inside the inspection compartment.

According to a preferred aspect of the present disclosure, the fermentation tank comprises a bottom and a cover. According to such an aspect, the internal wall is associated with said bottom and said cover. It follows that, preferably, the inspection compartment can extend from the bottom of the fermentation tank to the cover. In other words, the inspection compartment comprises a first terminal portion, or bottom terminal portion, associated with the bottom of the fermentation tank, and a second terminal portion, or top terminal portion, associated with the cover.

It follows that, advantageously, the fermentation environment is delimited not only by the external and internal walls, but also by the bottom and the cover. Furthermore, the compartment extends vertically inside the internal wall of the fermentation plant. It follows that it is advantageously possible to access the compartment from the outside of the fermentation environment, for example from the top of the cover.

According to a further preferred aspect of the present disclosure, the cover comprises a plurality of tie elements and a closure element of the fermentation environment which is supported by the tie elements themselves. Furthermore, such tie elements comprise a first terminal zone associated with the external wall of the fermentation tank and a second terminal zone associated with the internal wall of the fermentation tank.

Consequently, said inspection compartment delimited by the internal wall of the fermentation tank, in addition to allowing the inspection and maintenance of the bearing and the support of the stirrer shaft, acts as a support for covering the fermentation environment.

According to a preferred aspect, the inspection compartment comprises fluidic insulation means associated with the internal wall at the cover of the fermentation tank. Advantageously, the fluidic insulation means prevent the entry of gases produced by the fermentation into the inspection compartment.

According to a preferred aspect of the present disclosure, the fluidic insulation means comprise a lid of the inspection compartment and a support element of said lid. Preferably, the support element defines a sealing region configured to contain a fluid and to support the lid.

According to a preferred aspect, the inspection compartment has a substantially hexagonal section.

Such a shape allows the simplified installation of a variable number of stirrers inside the fermentation tank and allows to obtain an optimal angle between stirrers arranged consecutively in said fermentation tank.

According to a further preferred aspect of the present disclosure, the fermentation tank has a substantially circular section and the inspection compartment is arranged in a central area of the fermentation tank. The present disclosure has as a further object a management method of a fermentation plant for the fermentation of a material to be fermented. Such a method comprises a step of providing a fermentation tank having an external wall defining a fermentation environment in the fermentation tank, in which such fermentation environment is configured to contain a material to be fermented. The method further comprises a step of providing an internal wall configured to define an inspection compartment in the fermentation tank. The method comprises a further step of providing a stirrer configured to stir the material to be fermented in the fermentation environment. Said stirrer comprises a shaft rotatable around an axis of rotation and a first and a second terminal zone, in which the second terminal zone is opposite to the first terminal zone. In particular, the first terminal zone is supported by the external wall of the fermentation tank, while the second terminal zone is at least partially received in the inspection compartment.

It follows that the method object of the present disclosure allows a fermenter to be managed more easily. Specifically, ordinary or extraordinary maintenance or repair interventions, concerning in particular the second terminal zone of the shaft, are simplified.

According to an aspect of the present disclosure, the method comprises the step of providing an opening in the internal wall configured to at least partially receive the second terminal zone of the stirrer shaft. Preferably, the method further comprises a step of providing a sealing gasket in said opening. Specifically, the sealing gasket is interposed between the internal wall and the stirrer shaft so that the inspection compartment is fluidically isolated from the fermentation environment.

According to a preferred aspect of the present disclosure, the method further comprises the step of providing a supporting structure for the stirrer shaft inside the inspection compartment. In particular, the supporting structure is configured to support the second terminal zone of the shaft. Furthermore, the method preferably involves providing a bearing in said supporting structure. Such a bearing is configured to support the second terminal zone and to allow the rotation of the shaft. Advantageously, therefore, the second terminal portion of the shaft and in particular the bearing which supports it, can be inspected from the inspection compartment.

Preferably furthermore, the method also comprises the step of providing a second bearing, configured to support the first terminal zone of the shaft and to allow the rotation of the shaft itself, in the external wall of the fermentation tank.

According to a preferred aspect of the present disclosure, the method further comprises a step of providing a cover to the fermentation environment. In particular, the inspection compartment extends from a bottom of the fermentation tank to the cover, while the latter extends from the internal wall to the external wall of the fermentation tank.

According to a further aspect, the method comprises the step of providing the inspection compartment with fluidic insulation means. Preferably, such fluidic insulation means are associated with the internal wall at the cover of the fermentation tank and are configured to fluidically isolate the compartment from the fermentation environment. Furthermore, according to such an aspect, the fluidic insulation means comprise a lid for the inspection compartment and a support element for such a lid. In particular, such a support element defines a sealing region configured to contain a fluid and to support the cover.

Further advantages, features and methods of use of the object of the present disclosure will become evident from the following detailed description of the embodiments thereof, presented by way of non-limiting example.

It is however evident that each embodiment of the object of the present disclosure can present one or more of the advantages listed above; however, each embodiment is not required to simultaneously present all the listed advantages. Reference will be made to the figures of the accompanying drawings, in which:

- Figure 1 shows a plan view showing a perspective view of a fermentation plant according to an embodiment of the present disclosure;

- Figure 2 shows a perspective view of a fermentation plant according to an embodiment of the present disclosure in which tie elements for supporting the closure element of the fermentation environment are seen;

- Figure 3 shows a sectional side view of an inspection compartment of a fermentation plant according to an embodiment of the present disclosure;

- Figure 4 shows a sectional perspective view of an inspection compartment of a fermentation plant according to an embodiment of the present disclosure;

- Figure 5 shows a view of a detail of the fluidic insulation means of the inspection compartment of a fermentation plant according to an embodiment of the present disclosure.

With reference to the attached figures, an embodiment of a fermentation plant is indicated with the reference number 100.

As seen in Figure 1 and Figure 2, the fermentation plant 100 comprises a fermentation tank 10. Such a fermentation tank 10 comprises an external wall 11 which defines a fermentation environment 12 in the fermentation tank 10 which is configured to, in use, contain a material to be fermented. Preferably, such material to be fermented comprises natural substances, including, for example, manure and slurry, for the production of biogas. The fermentation plant 100 further comprises an internal wall 15 which is configured to define an inspection compartment 20 in the fermentation tank 10.

In the context of the present disclosure, the expression “inspection compartment” means an environment inside the fermentation tank 10. In other words, the inspection compartment 20 is placed in said fermentation environment 12 but separated from the latter by a wall, i.e. by the internal wall 15. In other words, the internal wall 15 defines, inside the fermentation tank 10, a closed room, preferably accessible from the outside of the fermentation tank 10, and separated, or divided, from the fermentation environment 12 configured to contain the material to be fermented. It follows that the fermentation environment 12 extends externally to said internal wall 15 but internally to the external wall 11 or, in other words, between the internal wall 15 and the external wall 11.

Specifically, the internal wall 15 is interposed between the fermentation environment 12 and said inspection compartment 20. Thereby, the inspection compartment is a room or environment located inside the fermentation tank 10 in which, preferably, neither the material to be fermented nor the gases produced by the fermentation of such material to be fermented enter.

According to a preferred aspect of the present disclosure, the external wall 11 of the fermentation tank 10 is preferably round. In other words, the fermentation tank 10 has a circular section. According to such an aspect, preferably, the inspection compartment 20 is arranged in a central area of said fermentation tank 10.

Furthermore, according to such an aspect, the fermentation compartment 20 is preferably arranged in the centre of the fermentation tank.

Preferably moreover, according to a further preferred aspect of the present disclosure, the inspection compartment 20 has a substantially hexagonal section. Consequently, the overall arrangement is such that the external wall 11 and the internal wall 15 define a fermentation environment 12 having a substantially doughnut-like shape.

The fermentation plant 100 further comprises a stirrer 30 configured to stir, or move, the material to be fermented inside the fermentation environment, so as to favour the release of biogas.

The stirrer 30 comprises a shaft 31 rotatable around an axis of rotation X. Preferably, the shaft 31 of the stirrer 30 extends along a main extension direction L arranged, in use, parallel to said axis of rotation X. Furthermore, the shaft 31 comprises a first terminal zone 32 and a second terminal zone 33, opposite said first terminal zone 32 along said main extension direction L. The stirrer further comprises a plurality of blades 34 which extend radially from said shaft 31. Each of said blades 34 is configured to stir, or mix, the material to be fermented.

According to an aspect of the present disclosure, the internal wall 15 comprises an opening configured to receive, or house, the second terminal zone 33 of the shaft

31 of the stirrer 30. In other words, said end is a hole in the internal wall 15 inside which the shaft 31 of the stirrer 30 can be at least partially inserted, in particular the second terminal zone 33 of said shaft 31.

Preferably, the opening of the internal wall comprises a sealing gasket. Such a sealing gasket is interposed between the internal wall 15 and the shaft 31 of the stirrer 30 so as to fluidically isolate the inspection compartment 20 from the fermentation environment. In other words, the gasket prevents the gases and the material to be fermented contained in the fermentation environment 12 from entering the inspection compartment 20.

Preferably moreover, the external wall 11 of the fermentation tank 10 comprises a second opening configured to receive, or house, at least partially, the first terminal zone 32 of the shaft 31 of the stirrer 30.

Furthermore, such a first terminal zone 32 of the shaft 31 is preferably supported by the external wall 11 of the fermentation tank 10.

The second terminal zone 33 of the shaft 31 is instead supported by a supporting structure 60 of the fermentation plant 100. Such a supporting structure 60 is configured to support the second terminal portion 33 of the shaft 31 and is arranged inside the inspection compartment 20 so that it can be inspected without having to empty the inspection environment 12.

The supporting structure 60 preferably comprises a bearing 17 configured to support the second terminal zone 33 of the shaft 31 and to allow the rotation of the shaft 31 itself. It follows that such a bearing 17 is accessible from the compartment 20. Thereby, the maintenance or repair operations at the second terminal zone 33 of the shaft 31 are simplified. For example, the bearing 17 can be lubricated from the inspection compartment 20 without having to empty the fermentation environment 12.

Furthermore, according to an aspect of the present disclosure, the external wall 11 comprises a second bearing 16 configured for supporting the first terminal zone

32 of a shaft 31 of a stirrer 30 and to allow the rotation of said shaft 31 around said axis of rotation X.

In other words, the stirrer 30 is arranged between said supporting structure 60 and said external wall 11 and the presence of said bearings 16, 17 allows the rotation of the shaft 31 around the rotation axis X. Preferably, such an axis of rotation X extends radially with respect to a fermentation tank 10 having a circular section.

Preferably, the inspection compartment has a substantially hexagonal section. In other words, the internal wall 15 defines a hexagonal environment. Such a configuration is particularly advantageous in that it allows the arrangement in the fermentation environment of a variable number of stirrers 30, with angles between one stirrer 30 and the next which allow an optimal mixing of the substance to be fermented. For example, according to a preferred embodiment, the fermentation plant 30 comprises three stirrers 30 angled to each other at an angle of 120°.

Thereby, maintenance operations, for example lubrication, on both support bearings of each stirrer are simplified and do not require emptying the fermentation environment 12 of the material to be fermented. In fact, the second bearing 16 is accessible from the outside of the external wall 11, or from the outside of the fermentation tank 10, or from outside the fermentation environment 12. The bearing 17 is instead accessible from the inspection compartment 20, i.e., from the inside of the internal wall 15.

According to a preferred aspect of the present disclosure, the fermentation tank 10 comprises a bottom 18 and a cover 40. It therefore follows that the fermentation tank 10 is delimited not only by the external wall 11 and the internal wall 15, but also by the bottom 18 and the cover 40.

According to such an aspect, the inspection compartment 20 comprises a first terminal portion, or bottom portion 21, and a second terminal portion, or top portion 22, opposite to the first terminal portion 21 and associated with the cover 40. In particular, the internal wall 15 is associated with the bottom 18 of the fermentation tank 10 and with the cover 40. Preferably, the inspection compartment 20 extends along a main extension direction preferably perpendicular to said bottom 18. In other words, the inspection compartment extends along a main vertical direction.

Advantageously, therefore, it is possible to access the inspection compartment 20 from the outside of the fermentation tank 10, preferably through the second terminal portion 22 which is associated with the cover 40.

According to one aspect of the present disclosure, the cover 40 comprises a plurality of tie elements 41. Each of such tie elements 41 comprises a first terminal zone 41a which is associated with the external wall 11 and a second terminal zone 41b which is associated with the internal wall 15 of the fermentation tank 10. In other words, each tie element of the plurality of tie elements 41 extends from the external wall 11 to the internal wall 15. According to a preferred embodiment, the tie elements 41 extend radially from the inspection compartment 20 to the external wall 11 of the fermentation tank 10.

The cover 40 further comprises a closure element 42 of the fermentation environment 12 which is supported by the tie elements 41.

Thereby, the second terminal portion 22 of the inspection compartment 20 defines an access opening to the inspection compartment 20 itself accessible from the cover 40 of the fermentation plant 100.

With particular reference to Figure 5, according to a further aspect of the present disclosure, the inspection compartment 20 comprises fluidic insulation means 50 located at the second terminal portion 22 of the inspection compartment 20 itself. Such fluidic insulation means 50 are configured to isolate the inspection compartment 20 from the fermentation environment 12, for example with respect to the gases contained, in use, in said fermentation environment 12.

According to one aspect, such fluidic insulation means 50 comprise a lid 51 of the inspection compartment 20. Preferably, such a lid 51 is supported by a support element 52.

In particular, according to a preferred aspect, the support element 52 of the lid 51 defines a sealing region 53. In use, such a sealing region 53 is configured to contain a fluid and to support the lid 51. In other words, the support element 52 is configured to define a basin in turn configured, in use, to contain a fluid. Furthermore, in operation, the lid 51 is associated in this basin defined by the support element 52.

The present disclosure has as a further object a management method for managing a fermentation plant 100 for the fermentation of a material to be fermented.

In describing such a process, the elements of the fermentation plant 100 involved in the method and having the same function and the same structure as the elements previously described retain the same reference number and are not described again in detail.

The method object of the present disclosure comprises a step of providing a fermentation tank 10, in which said fermentation tank 10 has an external wall 11 which defines a fermentation environment 12 inside the fermentation tank 10.

The method further comprises a step of providing, in the fermentation environment 12, an internal wall 15 configured to define an inspection compartment 20 in the fermentation environment 12. In particular, the internal wall 15 separates the inspection compartment 20 from the fermentation environment 12.

Furthermore, the method comprises a step of providing a stirrer 30 configured to stir the material to be fermented in the fermentation environment 12. Said stirrer 30 comprises a shaft 31 rotatable around an axis of rotation X and a first and a second terminal zone, 32 and 33 respectively, in which the second terminal zone 33 is opposite to the first terminal zone 32. The stirrer 30 is arranged so that the first terminal zone 32 of the shaft 31 is supported by the external wall 11 of the fermentation tank 10, and that the second terminal zone 33 of the shaft 31 is at least partially housed in the inspection compartment 20.

Advantageously therefore, the management of the fermentation plant has an inspection compartment which facilitates maintenance interventions, in particular in the region of the second terminal zone 33 of the shaft 31.

Preferably, the method comprises a step of providing an opening in the internal wall 15. Such an opening is configured to at least partially receive the second terminal zone 33 of the shaft 31. Preferably, the method further includes providing a sealing gasket in said opening, so that the inspection compartment 20 is isolated from the fermentation environment 12.

According to a preferred aspect of the present disclosure, the method includes providing a supporting structure 60 inside the inspection compartment 20. Such a supporting structure is configured to support the second terminal zone 33 of the shaft 31. Preferably, moreover, the method includes providing a bearing 17 in such a supporting structure 17 to support the second terminal zone 33 of the shaft 31 and to allow the rotation of the shaft 31 itself.

Furthermore, preferably, the method includes a step of providing a bearing 17 in such an opening of the internal wall 15 for supporting and rotating the shaft 31.

According to a preferred aspect of the present disclosure, the method comprises a step of providing a second bearing 16 for supporting the shaft 31 of the stirrer 30. More specifically, the second bearing 16 is arranged in the external wall 11 of the fermentation tank 10 so as to support the first terminal zone 32 of the shaft 31 of the stirrer 30.

According to a preferred aspect, the method comprises a step of providing a cover 40 to the fermentation environment 12. Preferably, the inspection compartment 20 is arranged inside the external wall 11 of the fermentation tank 10 so as to extend from a bottom 18 of such a fermentation tank 10 to such a cover 40. Furthermore, preferably, the cover 40 extends from the internal wall 11 to the external wall of the fermentation tank 10. It is thereby possible to access the inspection compartment 20 through the cover 40.

According to a further preferred aspect of the present disclosure, the method comprises a step of providing the inspection compartment 20 with fluidic insulation means 50. Preferably, the fluidic insulation means 50 are associated with the internal wall 15 at the cover 40 of the fermentation tank 10. According to such an aspect, said fluidic insulation means 50 comprise a lid 51 of the inspection compartment 20 and a support element 52 for said lid 51. In particular, such a support element 52 defines a sealing region 53 configured, in use, to contain a fluid and to support the cover 51. Advantageously, therefore, the provision of such fluidic insulation means allows to isolate the interior of the internal wall 15, i.e. , the inspection compartment 20, from the gases produced during the fermentation inside the fermentation environment 12. The overall configuration of the fermentation plant 100 is therefore such that it is possible to carry out maintenance interventions in the support zones of the stirrer shaft 30 without the need to empty the fermentation environment 12 of the material to be fermented. More specifically, the first support of the stirrer 30, i.e., the second bearing 16, is accessible from the outside of the external wall 11, i.e., from the outside of the fermentation tank 10. The second support of the stirrer 30, i.e., the bearing 17, is instead accessible from the inside of the internal wall 15, i.e., from the inspection compartment 20.

The object of the present disclosure has so far been described with reference to the embodiments thereof. It is to be understood that there may be other embodiments which relate to the same inventive nucleus, all falling within the scope of protection of the claims provided below.

Claims

- 1 -CLAIMS

1. Fermentation plant (100) comprising a fermentation tank (10) having an external wall (11) defining a fermentation environment (12), wherein said fermentation environment (12) is configured to contain a material to be fermented, the fermentation plant (100) further comprising an internal wall (15) configured to define an inspection compartment (20) in said fermentation tank (10), the fermentation plant (100) comprising a stirrer (30) configured to stir the material to be fermented in said fermentation environment (12), wherein the stirrer (30) comprises a shaft (31) rotatable around an axis of rotation (X), said shaft (31) comprising a first terminal zone (32) and a second terminal zone (33) opposite to said first terminal zone (32), wherein said first terminal zone (32) is supported by said external wall (11) of the fermentation tank (10) and wherein said second terminal zone (33) is at least partially housed in said inspection compartment (20).

2. Fermentation plant (100) according to the preceding claim, wherein said internal wall (15) comprises an opening configured to receive at least partially the second terminal zone (33) of the shaft (31) of the stirrer (30).

3. Fermentation plant (100) according to the preceding claim, wherein said opening comprises at least one sealing gasket.

4. Fermentation plant (100) according to any one of the preceding claims, comprising a supporting structure (60) configured to support the second terminal zone (33) of the shaft (31), wherein said supporting structure (60) is arranged inside the inspection compartment (20).

5. Fermentation plant (100) according to the preceding claim, wherein said supporting structure (60) comprises a bearing (17) configured to support said second terminal zone (33) of the shaft (31) and to allow rotation of the shaft (31).

6. Fermentation plant (100) according to any one of the preceding claims, wherein said external wall (11) comprises a second bearing (16) configured to support the first terminal zone (32) of the shaft (31) and to allow the rotation of the shaft (31).

7. Fermentation plant (100) according to any one of the preceding claims, wherein the fermentation tank (10) comprises a bottom (18) and a cover (40) and wherein said internal wall (15) is associated with said bottom (18) and to said cover (40).

8. Fermentation plant (100) according to the preceding claim, wherein said cover comprises a plurality of tie elements (41) and a closure element (42) of the fermentation environment (12), wherein each tie element (41) of the plurality of tie elements (41) comprises a first terminal zone (41a) associated with said external wall (11) and a second terminal zone (41b) associated with said internal wall (15) of 2 the fermentation tank (10) and wherein said plurality of tie elements (41) is configured to support said closure element (42).

9. Fermentation plant (100) according to claim 6 or 7, wherein said inspection compartment (20) comprises fluidic insulation means (50) associated with said internal wall (15) at said cover (40) of the fermentation tank (10), wherein said fluidic insulation means are configured to fluidically isolate said compartment (20) from the fermentation environment (12).

10. Fermentation plant (100) according to the preceding claim, wherein said fluidic insulation means (50) comprise a lid (51) of said inspection compartment (20) and a support element (52) for said lid (51).

11. Fermentation plant (100) according to the preceding claim, wherein the support element (52) defines a sealing region (53) configured to contain a fluid and to support said lid (51).

12. Fermentation plant (100) according to any one of the preceding claims, wherein said inspection compartment (20) has a substantially hexagonal section.

13. Fermentation plant (100) according to any of the preceding claims, wherein said fermentation tank (10) has a substantially circular section and wherein said inspection compartment (20) is arranged in a central area of said fermentation tank (10).

14. Management method for managing a fermentation plant (100) for the fermentation of a material to be fermented comprising the steps of:

- providing a fermentation tank (10) having an external wall (11) defining a fermentation environment (12) in said fermentation tank (10) wherein said fermentation environment (12) is configured to contain a material to be fermented;

- providing, in said fermentation environment (12), an internal wall (15) configured to define an inspection compartment (20) in said fermentation environment (12);

- providing a stirrer (30) configured to stir the material to be fermented in said fermentation environment (12), wherein said stirrer (30) comprises a shaft (31) rotatable around an axis of rotation (X), said shaft (31) comprising a first terminal zone (32) and a second terminal zone (33) opposite to said first terminal zone (32), wherein said first terminal zone (32) is supported by said external wall (11) of the fermentation tank (10) and wherein said second terminal zone (33) is at least partially housed in said inspection compartment (20).

15. Method according to the preceding claim, comprising the step of providing an opening in the internal wall (15), wherein said opening is configured to receive at least partially the second terminal zone (33) of the shaft (31) of the stirrer (30), said method further comprising the step of providing a sealing gasket in said opening. - 3

16. Method according to claim 14 or 15, comprising the step of providing a supporting structure (60) configured to support the second terminal zone (33) of the shaft (31) and arranging said supporting structure (60) inside said inspection compartment (20).

17. Method according to the preceding claim, comprising the step of providing a bearing (17) in said supporting structure (60), said bearing (17) being configured to support the second terminal zone (33) of the shaft (31) and to allow the rotation of the shaft (31).

18. Method according to any one of claims from 14 to 17, further comprising the step of providing the fermentation environment (12) with a cover (40), wherein said internal wall (15) extends from a bottom (18) of said fermentation tank (10) to said cover (40), and wherein said cover (40) extends from said internal wall (15) to said external wall (11) of the fermentation tank (10).

19. Method according to one of claims from 14 to 18, further comprising the step of supplying said inspection compartment (20) with fluidic insulation means (50), wherein said fluidic insulation means (50) comprise a lid (51) of said inspection compartment (20) and a support element (52) for said lid (51), wherein said support element (51) defines a sealing region (53) configured to contain a fluid and to support said lid (51).

20. Method according to one of claims from 14 to 19, further comprising the step of providing in said external wall (11) a second bearing (16) configured to support the first terminal zone (32) of the shaft (31) of the stirrer(30) and to allow rotation of the shaft (31).