Device and method for taking samples from a fermenter of a biogas plant and method for assembling such a device

Abstract

A device (30) and a method for taking samples (20) from a fermenter (10) of a biogas plant, as well as a method for assembling such a device (30), are disclosed. The fermenter (10) has a concrete wall (13) that encloses a fermentation chamber (11) and in which a test core (20) produced by means of a concrete core drilling is inserted. The device (30) comprises a metal pipe stub (31) that has an inner surface (32) and an outer surface (33) and extends from a proximal end (34) facing the fermenter (10) to a distal end (35).The device (30) further comprises a first flange plate (36) arranged at the proximal end (34) of the pipe stub (31), a second flange plate (37) arranged at the distal end (35) of the pipe stub (31), a cover flange (38) which can be placed on the second flange plate (37) in a gas-tight manner, and a fastening element (41) which is attached to the cover flange (38) and can be connected to the test core (20).

Description

[0001] The invention relates to a device and a method for taking samples from a fermenter of a biogas plant. The invention further relates to a method for mounting such a device on a fermenter of a biogas plant.

[0002] A fermenter for a biogas plant with at least one stirring device is described in DE 20 2004 004 101 U1. A vertically arranged fermenter is known from DE 20 2018 101 574 U1.

[0003] The device for taking samples from the inner wall of biogas tanks serves to check tank integrity and concrete quality. The device is designed to meet the highest requirements for gas tightness and fire protection and is specifically designed for use in potentially explosive atmospheres within biogas plants.

[0004] Current technologies for taking samples from tank walls often do not offer the necessary protection against gas emissions that occur in a biogas tank. In particular, devices that provide both reliable gas tightness and fire-resistant construction to meet the requirements of the ATEX (Atmospheres Explosives) Directive and fire resistance classes are lacking.

[0005] Existing solutions such as those known from CN 210595712 U or DE 20 2011 104 136 U1 are insufficient because they are not designed for the removal of concrete cores under gas-tight and fire-protection-relevant conditions.

[0006] Furthermore, DE 20 2009 004 669 U1 describes a method for preventing deposits in biogas fermenter construction caused by sinking substances.

[0007] A biogas plant for the production of biogas by anaerobic wet fermentation of a biomass-containing substrate in a single-stage flow-through process is described in DE 20 2008 017 612 U1.

[0008] Furthermore, DE 20 2005 011 689 U1 discloses a gas seal for sealing the upper opening of a large-volume container which has a wall surrounding the opening. The gas seal comprises a gas storage film whose edge rests against the wall, at least four pressure plates mounted around the upper edge of the wall, and a sealing cord. The edge of the gas storage film is folded over, and the sealing cord is inserted around the entire circumference into the folded-over gas storage film. The pressure plates compress the gas storage film in its folded-over area against the upper edge of the wall.

[0009] DE 20 2011 104 136 U1 describes a device for closing an access opening in a wall made of fire-resistant material. The device comprises an outer frame made of fire-resistant material, which can be attached to the outside of the access opening to be closed, and an access cover made of fire-resistant material, which can be detachably attached to the outer frame and is designed in multiple parts and, when attached, completely covers the opening of the outer frame on the outside.

[0010] DE 10 2018 213 450 A1 discloses a method for mounting a sensor module in a reactor vessel of a biogas plant that is at least partially loaded or loadable with fermentable material. The method comprises the following steps: mounting a flange with an attached pipe stub on an outer surface of the reactor vessel wall at the intended installation position of the sensor; opening a closure device arranged on the pipe stub that variably closes, opens, or releases a passage in the pipe stub; inserting a drill bit into the pipe stub with the passage open and drilling through the wall to create a through-bore extending into an interior of the reactor vessel; withdrawing the drill bit from the pipe stub and immediately closing the closure device.Opening the closure device and immediately thereafter mounting a sensor module, the module shaft of which is positioned in a largely sealing manner in the passage of the pipe stub, wherein at least one sensor provided and / or designed for detecting at least one parameter of the fermentation substrate located in the reactor vessel is arranged on a section of the module shaft projecting into the interior of the reactor vessel.

[0011] DE 103 06 988 A1 discloses a process for the fermentation of biomass with the production of biogas, in which the supply of biomass to a fermentation chamber and the removal of biogas and residual substrate take place in a continuous operation.

[0012] A biogas plant for the treatment of organic materials with the participation of microorganisms, which result in the production of biogas, is described in DE 20 2007 018 608 U1. The plant comprises a gas-tight sealable reactor, the interior of which has at least a partially enlarged surface area for colonization by microorganisms.

[0013] WO 2021 / 170 162 A1 discloses a device for the production and temporary storage of biogas, in which a fermenter, when installed, transitions directly upwards into a biogas collection chamber. The transition between the fermenter and the biogas collection chamber is determined by the fill level of the biogas substrate to be fermented. The fermenter and the biogas collection chamber are integrally connected and consist of a foldable, tear-resistant, flexible textile fabric coated with a gas- and liquid-tight coating.

[0014] A process for the anaerobic production of biogas from a fermentable substrate, using at least two separate fermentation tanks, is described in WO 2018 / 064 993 A1.

[0015] Finally, WO 2015 / 090 261 A1 reveals a modular system for the construction of a biogas fermenter.

[0016] The invention is based on the objective of providing a device for the gas-tight and fire-safe extraction of concrete cores from biogas tanks. In particular, it aims to enable the safe extraction of samples without the escape of explosive gases. The device should also meet the requirements for fire resistance, corrosion resistance, and durability, especially in aggressive environments such as biogas plants.

[0017] This problem is solved by a device according to claim 1 and a method according to claims 12 and 20. Preferred embodiments of the invention are the subject of claims 2 to 11, 13 to 19, 21 and 22.

[0018] The device according to the invention is used for taking samples from a fermenter of a biogas plant. The fermenter has a concrete wall enclosing a fermentation chamber in which a test core, produced by means of a concrete core drilling, is inserted. The wall has an inner surface and an outer surface. The device comprises a metal pipe stub, which has an inner and an outer surface and extends from a proximal end facing the fermenter to a distal end. A first flange plate, arranged at the proximal end of the pipe stub, can be attached to the outer surface of the fermenter wall such that the test core is located in the area of ​​the pipe stub. A second flange plate is arranged at the distal end of the pipe stub. A cover flange can be placed gas-tight onto the second flange plate. A fastening element is attached to the cover flange and can be connected to the test core.

[0019] In a preferred embodiment, the device further comprises a blind flange which can be placed gas-tight on the second flange plate in place of the cover flange.

[0020] In a preferred embodiment, the device further comprises a gasket arranged between the second flange plate and the cover flange or between the second flange plate and the blind flange. The gasket is preferably designed as a sealing plate. The gasket has a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or a width in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or a thickness in the range of 2 mm to 10 mm, preferably in the range of 4 mm to 6 mm. The gasket preferably has a centrally arranged opening for receiving the pipe stub, the diameter of which is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm. The gasket is preferably made of a synthetic rubber, in particular nitrile butadiene rubber.

[0021] Preferably, the device further comprises a threaded rod and a spacer sleeve, wherein the fastening element is attached to the cover flange by means of the threaded rod and the spacer sleeve. Preferably, the fastening element is designed as a first fixed anchor.

[0022] In a preferred embodiment, the device further comprises at least one additional, second fixing anchor, wherein the first flange plate can be attached to the outer surface of the fermenter by means of the second fixing anchor.

[0023] Preferably, the device comprises at least one screw connection, wherein the cover flange and / or the blind flange are detachably connected to the second flange plate by means of the screw connection.

[0024] Advantageously, the pipe stub and / or the first flange plate and / or the second flange plate and / or the cover flange and / or the blind flange and / or the first fixed anchor and / or the second fixed anchor and / or the threaded rod and / or the spacer sleeve and / or the screw connection are made of a stainless steel, preferably stainless steel, and further preferably of alloy 1.4301 (X5CrNi18-10).

[0025] Preferably, the pipe stub has a diameter in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm, and / or a length in the range of 50 mm to 150 mm, preferably in the range of 60 mm to 100 mm, and / or a wall thickness in the range of 1 mm to 5 mm, preferably in the range of 2 mm to 3 mm.

[0026] Preferably, the first flange plate has a length in the range of 150 mm to 800 mm, preferably in the range of 300 mm to 400 mm, and / or a width in the range of 150 mm to 800 mm, preferably in the range of 300 mm to 400 mm, and / or a thickness in the range of 2 mm to 10 mm, preferably in the range of 3 mm to 6 mm. The first flange plate preferably has a centrally arranged opening for receiving the pipe stub, the diameter of which is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm. Furthermore, the first flange plate expediently has at least one opening, preferably four to ten openings, for receiving the second fixing anchor(s).

[0027] Preferably, the second flange plate has a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or a width in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or a thickness in the range of 2 mm to 12 mm, preferably in the range of 5 mm to 10 mm. Furthermore, the second flange plate preferably has a centrally arranged opening for receiving the pipe fitting, the diameter of which is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm. The second flange plate expediently has at least one opening, preferably four to ten openings, for receiving the bolted connection.

[0028] Preferably, the cover flange and / or the blind flange have a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or a width in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and a thickness in the range of 2 mm to 12 mm, preferably in the range of 5 mm to 10 mm. Furthermore, the cover flange and / or the blind flange have at least one opening, preferably four to ten openings, for receiving the bolted connection.

[0029] The method for mounting the device according to the invention on a fermenter of a biogas plant comprises the following process steps: ▪ Attaching the first flange plate to the outer surface of the fermenter above the fill level of a fermentation substrate in the fermentation chamber of the fermenter; ▪ Performing a concrete core drilling, in particular through the pipe stub, and removing the core sample obtained from the borehole in the wall of the fermenter; ▪ Applying a coating to the borehole rim and borehole wall; ▪ Applying a coating to the drill core, leaving the end face of the drill core exposed that faces the fermentation chamber of the fermenter, to form a test drill core; ▪ Attaching the test core to the cover flange; ▪ Inserting the test core into the borehole while simultaneously placing the cover flange onto the second flange plate; ▪ Gas-tight connection of the cover flange and the second flange plate.

[0030] In a preferred embodiment, the procedure further comprises the following procedural steps: ▪ Checking the device for leaks, preferably using a gas detector or a leak detection spray or a foaming agent; ▪ wherein the device is preferably checked for leaks at regular intervals, in particular monthly.

[0031] Preferably, prior to the process step of attaching the first flange plate to the outer surface of the fermenter, a lining of the fermenter is removed, at least in the area where the first flange plate is to be attached, so that the outer surface of the wall is exposed.

[0032] Furthermore, in the process step of attaching the first flange plate to the outer surface of the fermenter, the first flange plate is preferably attached to the outer surface of the fermenter by means of the second fixing anchor, preferably by means of a plurality of second fixing anchors, and further preferably by means of eight second fixing anchors.

[0033] Preferably, a concrete core drilling with a diameter of 50 mm to 350 mm, preferably 100 mm to 200 mm, is carried out.

[0034] Furthermore, a coating made of an acid-resistant and / or fire-resistant material, preferably sodium silicate, is preferably applied to the borehole edge and the borehole wall and / or to the drill core.

[0035] When attaching the test core to the cover flange, the first fixing anchor is advantageously placed centrally on the end face of the test core, the side facing away from the fermentation chamber of the fermenter, and preferably connected to the cover flange by means of the threaded rod and the spacer sleeve. A distance corresponding to the length of the pipe stub is maintained between the test core and the cover flange. Preferably, this distance is between 50 mm and 150 mm, and more preferably between 60 mm and 100 mm.

[0036] Advantageously, to connect the cover flange and the second flange plate, the gasket is placed between the second flange plate and the cover flange, and the cover flange and the second flange plate are then connected to each other by means of the screw connection, so that the device is sealed gas-tight.

[0037] The method for taking samples from a fermenter of a biogas plant using the device according to the invention comprises the following process steps: ▪ Detaching the cover flange from the second flange plate; ▪ Extracting the test core from the borehole in the wall of the fermenter; ▪ Placing the blind flange onto the second flange plate; ▪ Gas-tight connection of blind flange and second flange plate; ▪ Examination of the test core outside the fermenter; ▪ Detaching the blind flange from the second flange plate; ▪ Inserting the test core into the borehole while simultaneously placing the cover flange onto the second flange plate; ▪ Gas-tight connection of the cover flange and the second flange plate; ▪ Check the device for leaks.

[0038] In a preferred embodiment, the method further comprises the following process step: ▪ Checking the device for leaks after gas-tight connection of the blind flange and second flange plate, preferably using a gas detector or a leak detection spray or a foaming agent.

[0039] It is advisable that, after checking the device for leaks in the individual process steps, any leaks are sealed with a sealant.

[0040] The invention is explained below with reference to an exemplary embodiment. The drawings, which schematically depict the exemplary embodiment, show in detail: Fig. 1 a schematic representation of a fermenter of a biogas plant; Fig. 2 an enlarged view of the in Fig. 1 with area marked II, which shows the device according to the invention, and Fig. 3 a section through the device according to the invention Fig. 2.

[0041] The in Fig. The fermenter 10 shown in Figure 1 of a biogas plant is the heart of the process in which organic material is converted into biogas (BG). This process is called anaerobic fermentation because it takes place without oxygen. The operation of the fermenter 10 is as follows: The Fermenter 10 is filled with organic waste or biomass, which serves as the so-called fermentation substrate (GS) for the production of biogas (BG). This biomass can consist of agricultural residues, kitchen waste, energy crops, or manure. The Fermenter 10 can also be filled with a mixture of different materials to achieve optimal results.

[0042] The fermenter 10 is typically controlled to create the right conditions for the anaerobic microbes. This includes, in particular, the temperature: In most biogas plants, the operating temperature is around 35°C to 40°C, so-called mesophilic temperatures, or 50°C to 60°C, so-called thermophilic temperatures, to promote microbial activity. Furthermore, the pH value must be within the optimal range, usually between 6.5 and 8, to support the microbes. The moisture content is adjusted so that the microbes in the fermenter 10 can carry out their activities.

[0043] Inside fermenter 10, fermentation chamber 11, the anaerobic decomposition of biomass by microbes takes place. This process occurs in several steps: Hydrolysis: Complex organic molecules, such as polysaccharides, proteins and fats, are broken down by microbial enzymes into simpler compounds, such as sugars, amino acids, and fatty acids. Acidogenesis: These simple compounds are further broken down by acidogenic bacteria and converted into organic acids, hydrogen and CO2. Acetogenesis: The organic acids are converted into acetate, hydrogen and CO2 by acetogenic bacteria. Methanogenesis: In the final stage of fermentation, methanogenic bacteria convert acetate and hydrogen into methane (CH4) and CO2, producing biogas BG.

[0044] The biogas BG, which, as previously described, consists primarily of methane (approximately 50% to 70%) and CO2 (approximately 30% to 50%), is collected in the upper part of digester 10 and is typically discharged via a special pipe system. Methane is the main component of biogas BG and is used as a renewable energy source. After fermentation, a solid digestate remains in digester 10. This digestate contains nutrients that can still be used as fertilizer. In many biogas plants, this digestate is regularly removed and spread on fields as organic fertilizer or further processed.

[0045] Modern fermenters are typically equipped with automated control systems that monitor and adjust parameters such as the agitator, temperature, pH value, humidity, and other important parameters. This ensures that the conditions for the microbes are always optimal, resulting in efficient biogas production.

[0046] The wall 13 of fermenter 10 must be regularly inspected to ensure the reliable operation of the biogas plant. Regular inspection of the wall 13 of fermenter 10 is crucial for safety, the efficiency of biogas production, and the long-term functionality of the biogas plant. Its primary purpose is to prevent leaks, detect corrosion, verify structural integrity, and ensure that conditions in the fermentation chamber 11 of fermenter 10 remain optimal.

[0047] The wall 11 of the digester 10 must be airtight to prevent the escape of biogas BG. As explained, biogas BG contains methane, which is highly flammable and potentially hazardous. A leak in the wall 13 could lead to a dangerous accumulation of methane and thus to a significant risk of explosion or fire. Regular inspection of the wall 13 is essential to ensure that it remains intact and airtight.

[0048] Biogas plants operate under humid and often aggressive conditions, which can attack the wall 13 of the digester 10. The acids and gases produced during the fermentation process can corrode or weaken materials. Damaged wall 13 can lead to leaks or even structural problems.

[0049] Furthermore, the wall 13 of the fermenter 10 influences the temperature and pressure conditions inside the fermentation chamber 11. If the wall 13 is damaged, heat can be lost, leading to a temperature drop in the fermenter 10. An insufficient temperature can impair the activity of the microbes and thus reduce the efficiency of biogas BG production. Regular inspection ensures that the wall 13 retains its insulating properties and that optimal conditions for the fermentation process are maintained.

[0050] Wall 13 must be strong and stable enough to withstand the pressure and stresses caused by the biomass and the gases produced. Cracks or other damage to the structure can destabilize the entire construction. Regular inspection of wall 13 helps to identify and repair weaknesses early, before they lead to more serious problems.

[0051] The wall 13 of the fermenter 10 is also exposed to environmental influences, such as temperature fluctuations, humidity, or mechanical stress. Regular inspection makes it possible to monitor these influences and prevent them from causing damage to the structure.

[0052] Regular inspections allow for the early identification of maintenance and repair needs. This is important to avoid costly repairs and to maintain or even extend the service life of the digester 10. Addressing minor damage promptly can prevent more extensive downtime of the biogas plant.

[0053] The in the Fig. 2 and Fig. 3. Device 30, shown in more detail, serves to take samples 20 from the concrete wall 13 of the fermenter 10 and thus to check the wall 13 of the fermenter 10, which is crucial for the safety, the efficiency of the production of biogas BG and the long-term functionality of the biogas plant.

[0054] The device 30 comprises a metal pipe stub 31, which has an inner surface 32 and an outer surface 33 and extends from a proximal end 34 facing the fermenter 10 to a distal end 35. The device 30 further comprises a first flange plate 36, which is arranged at the proximal end 34 of the pipe stub 31. The wall 13 has an inner surface 14 and an outer surface 15. The first flange plate 36 can be attached to the outer surface 15 of the wall 13 of the fermenter 10 such that the sample, a test core 20 produced by means of a concrete core drilling and inserted into the wall 13, is located in the area of ​​the pipe stub 31. A second flange plate 37 is arranged at the distal end 35 of the pipe stub 31.The device 30 also includes a cover flange 38, which can be placed on the second flange plate 37 in a gas-tight manner, and a first fastening element 41, which is attached to the cover flange 38 and can be connected to the test core 20.

[0055] In its assembled state, which is in the Fig. 2 and Fig. As shown in Figure 3, the cover flange 38 is connected to the test core 20 by means of the fastening element 41. For this purpose, the device 30 comprises a threaded rod 44 and a spacer sleeve 45 with an internal thread. The fastening element 41, preferably designed as a fixed anchor, is attached to the cover flange 38 by means of the threaded rod 44, which engages in the spacer sleeve 45 and is secured by a nut 46, so that the distance between the cover flange 38 and the wall 13 is adjustable and thus precise removal and reinsertion of the test core 20 into the wall 13 is ensured.

[0056] The device 30 further comprises a seal 40, which is arranged between the second flange plate 37 and the cover flange 38. The seal 40, preferably designed as a sealing plate, has a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm. The width of the seal 40 is in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and the thickness in the range of 2 mm to 10 mm, preferably in the range of 4 mm to 6 mm. The diameter of an opening, preferably arranged centrally, for receiving the pipe stub 31, which the seal 40 has, is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm. The seal 40 preferably consists of a synthetic rubber, in particular nitrile butadiene rubber.

[0057] The device 30 further comprises a second fastening element, which is designed as a fixing anchor 42. The first flange plate 36 can be fastened to the outer surface 15 of the fermenter 10 by means of a plurality of fixing anchors 42 and, in the assembled state, which is in the Fig. 2 and Fig. As shown in Figure 3, preferably attached to the outer surface 15 with eight fixing anchors 42. As shown in Figure 3. Fig. 2 and Fig. 3 further indicates that the device 30 comprises at least one screw connection 43 by means of which the cover flange 38 or a Fig. The two blind flanges, shown in dashed lines, are detachably connected to the second flange plate 37 instead of the cover flange 38. In the case of the Fig. In the embodiment shown in 2, there are four screw connections 43.

[0058] The pipe stub 31 and / or the first flange plate 36 and / or the second flange plate 37 and / or the cover flange 38 and / or the blind flange 39 and / or the first fixed anchor 41 and / or the second fixed anchors 42 and / or the threaded rod 44 and / or the spacer sleeve 45 and / or the screw connections 43 are made of a stainless steel, preferably stainless steel, and more preferably of the alloy 1.4301 (X5CrNi18-10).

[0059] The pipe fitting 31 has a diameter in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm, a length in the range of 50 mm to 150 mm, preferably in the range of 60 mm to 100 mm, and a wall thickness in the range of 1 mm to 5 mm, preferably in the range of 2 mm to 3 mm.

[0060] The first flange plate 36 has a length in the range of 150 mm to 800 mm, preferably in the range of 300 mm to 400 mm, a width in the range of 150 mm to 800 mm, preferably in the range of 300 mm to 400 mm, and a thickness in the range of 2 mm to 10 mm, preferably in the range of 3 mm to 6 mm. Furthermore, the first flange plate 36 has a preferably centrally arranged opening for receiving the pipe stub 31, the diameter of which is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm. The first flange plate 36 also has a plurality of openings for receiving the second fixing anchors 42. In the Fig. In the embodiment shown in 2, there are eight openings.

[0061] The second flange plate 37 has a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, a width in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and a thickness in the range of 2 mm to 12 mm, preferably in the range of 5 mm to 10 mm. Furthermore, the second flange plate 37 has a preferably centrally located opening for receiving the pipe fitting 31, the diameter of which is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm. The second flange plate 37 also has four openings for receiving the screw connections 43.

[0062] The cover flange 38 and the blind flange 39 each have a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, a width in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and a thickness in the range of 2 mm to 12 mm, preferably in the range of 5 mm to 10 mm. Furthermore, the cover flange 38 and the blind flange 39 each have four openings which serve to receive the screw connections 43.

[0063] The device 30 is mounted on the fermenter 10 of a biogas plant as follows.

[0064] First, the first flange plate 36, and thus the pipe fitting 31, is attached to the outer surface 15 of the fermenter 10, above the fill level 12 of the fermentation substrate GS in the fermentation chamber 11 of the fermenter 10. For this purpose, any lining of the fermenter 10 is removed, at least in the area where the first flange plate 36 is to be attached, so that the outer surface 15 of the wall 13 is exposed. The first flange plate 36 is attached to the outer surface 15 of the fermenter 10 by means of the eight second fixing anchors 42.

[0065] A concrete core drilling is then carried out, preferably through the pipe stub 31. Alternatively, the concrete core drilling can also be carried out with the pipe stub 31 removed, for example, before the first flange plate 36 is attached to the outer surface 15 of the fermenter 10, or by removing the pipe stub 31 again before the concrete core drilling. Subsequently, the core 20 obtained by the concrete core drilling, the diameter of which is between 50 mm and 350 mm, preferably between 100 mm and 200 mm, is removed from the borehole in the wall 13 of the fermenter 10, and a coating is applied to the borehole edge and the borehole wall. Furthermore, a coating is applied to the core 20, leaving the end face of the core 20, which faces the fermentation chamber 11 of the fermenter 10, exposed, thus forming the test core 20.The coating consists of an acid-resistant and / or fire-resistant material, preferably sodium silicate, so that especially the end face of the test core 20 is exposed unprotected to the humid and aggressive conditions prevailing in the fermentation chamber 11.

[0066] The test core 20 is then attached to the cover flange 38. For this purpose, the first fixing anchor 41 is preferably placed centrally on the end face of the test core 20 that faces away from the fermentation chamber 11 of the fermenter 10, i.e., the coated end face of the test core 20, and connected to the cover flange 38 by means of the threaded rod 44, the spacer sleeve 45, and the nut 46. A distance is maintained between the test core 20 and the cover flange 38 that corresponds to the length of the pipe stub 31 and is preferably between 50 mm and 150 mm, and more preferably between 60 mm and 100 mm. The spacer sleeve 45 makes it possible to adjust this distance precisely so that the test core 20 can be reinserted exactly into the borehole in the wall 13.

[0067] When the test core 20 is inserted into the borehole, the cover flange 38 is simultaneously placed onto the second flange plate 37. The cover flange 38 and the second flange plate 37 are then gas-tightly connected by placing the gasket 40 between the second flange plate 37 and the cover flange 38, and by connecting the second flange plate 37 and the cover flange 38 using the screw connections 43. This seals the device 30 gas-tight and prevents biogas BG from escaping the fermentation chamber 11 through the borehole.

[0068] Device 30 is then checked for leaks, for which a gas detector, leak detection spray, or a foaming agent is suitably used. The leak check of device 30 is repeated at regular intervals, approximately monthly. Leaks are sealed with a sealant.

[0069] The procedure for taking samples 20 from a fermenter 10 of a biogas plant using the device 30 is carried out as follows: First, the cover flange 38 is removed from the second flange plate 37 by loosening the bolted connections 43. Then, the test core 20 is extracted from the borehole in the wall 13 of the fermenter 10 using the cover flange 38. The blind flange 39 is then placed onto the second flange plate 37 and gas-tightly connected to it to prevent significant leakage of biogas BG from the fermentation chamber 11 through the borehole. Advantageously, the device 30 is checked for leaks, preferably using a gas detector, a leak detection spray, or a foaming agent, and any leaks are sealed with a sealant.

[0070] The test core 20 is examined outside the fermenter 10 in order to assess the need for maintenance and repair measures based on its condition.

[0071] The blind flange 39 is then removed from the second flange plate 37 by loosening the screw connections 43, and the test core 20 is reinserted into the borehole while the cover flange 38 is simultaneously placed onto the second flange plate 37. The cover flange 38 and the second flange plate 37 are connected gas-tight, and the device 30 is checked for leaks, preferably using a gas detector, a leak detection spray, or a foaming agent. Any leaks are sealed with a sealant.

[0072] The device 30 is characterized by a gas-tight and fire-safe extraction of test cores 20. The design and construction of the device 30 contribute to this. Preferably, the pipe fitting 31, a cylindrical element made of corrosion-resistant stainless steel 1.4301, has an inner diameter of 204 mm, a length of 60 mm, and is firmly connected to the wall 13 of the fermentation chamber 11. The pipe fitting 31 serves as a connecting element between the wall 13 of the fermentation chamber 11 and the extraction system consisting of the cover flange 38 and the test core 20. Preferably, the second flange plate 37 is a rectangular plate with dimensions of 340 mm x 340 mm, which is expediently welded onto the pipe fitting 31. It forms the primary sealing surface for the gas-tight attachment of the cover flange 38.

[0073] The sealing system comprises the gasket 40, which is positioned between the second flange plate 37 and the cover flange 38 and is designed as a flame-retardant rubber gasket with dimensions of 230 mm x 230 mm x 5 mm. The gasket 40 meets fire protection class B1 according to DIN 4102 and is resistant to high temperatures and chemical attack commonly found in biogas plants.

[0074] The cover flange 38, measuring 234 mm x 234 mm, is also made of stainless steel and is gas-tightly connected to the pipe fitting 31. It is connected to the flange plate 37 by the screw connections 43, for example M10 x 95 mm, to ensure a permanent, gas-tight connection. The cover flange 38 is designed to withstand an internal pressure of up to 2 bar during operation without any gas escaping.

[0075] The test core 20 has the same material composition as the concrete from which the fermentation chamber 11 is made and is attached to the cover flange 38 via the first fixing anchor 41. The test core 20 can be easily removed by loosening the cover flange 38. This allows for regular testing of the concrete quality without compromising the structural integrity of the fermenter 10. After removing the test core 20, the opening is sealed gas-tight with the stainless steel blind flange 39. The blind flange 39, together with the heat-resistant seal 40, prevents any gas loss even at temperatures up to 300 °C.

[0076] The entire device 30 comprises components made of non-combustible stainless steel 1.4301, which complies with the requirements of DIN EN 13501-1 for the classification of building materials. Stainless steel is not only corrosion-resistant but also heat-resistant, making it ideal for use in fire-sensitive areas. The seal 40 is flame-retardant and meets fire protection class B1 according to DIN 4102. The seal 40 ensures that, in the event of a fire, fire cannot spread through the opening. The device 30 meets the requirements of fire resistance class F90 according to DIN 4102, meaning it can withstand a fire exposure of at least 90 minutes without losing its functionality. This ensures that no gases escape even in the event of a fire and that the safety of the system remains guaranteed.

[0077] Device 30 is certified for use in potentially explosive atmospheres in accordance with ATEX Directive 2014 / 34 / EU. Its design minimizes the risk of sparking and, thanks to the gas-tight seal, prevents the escape of biogas, which could be potentially hazardous in the explosion area. All components are dimensioned to withstand the maximum pressure that can occur in fermentation chamber 11. The gas tightness of the connections has been tested and certified for operating pressures up to 2 bar.

[0078] The advantages of the device include, in particular, maximum gas tightness and compliance with the highest fire protection requirements. The Device 30 withstands fire exposure for at least 90 minutes and uses only materials that meet the strictest fire protection guidelines. Corrosion resistance: The use of stainless steel 1.4301 permanently protects the Device 30 from the corrosive environmental conditions found in fermenters. Durability: The Device 30 ensures long-term, low-maintenance use, even under harsh environmental conditions. Last but not least, the Device 30 guarantees explosion protection: The ATEX-compliant design ensures that the Device 30 can be operated safely even in potentially explosive atmospheres. Reference symbol list 10 fermenters 11 Fermentation chamber 12 Filling level 13 Wall 14 interior surface 15 outdoor area 16 Agitator 20 test cores 30 Device 31 pipe fittings 32 Inside 33 Outside 34 proximal end 35 distal end 36 first flange plate 37 second flange plate 38 Deck flange 39 Blind flange 40 Seal 41 first fixed anchor 42 second fixed anchor 43 Screw connection 44 threaded rod 45 Spacer sleeve 46 Screw nut GS fermentation substrate BG Biogas

Claims

[1] Device (30) for taking samples (20) from a fermenter (10) of a biogas plant, wherein the fermenter (10) has a concrete wall (13) enclosing a fermentation chamber (11) in which a test core (20) produced by means of a concrete core drilling is inserted, wherein the wall (13) has an inner surface (14) and an outer surface (15), comprising: a metal pipe fitting (31) which has an inside (32) and an outside (33) and extends from a proximal end (34) facing the fermenter (10) to a distal end (35); a first flange plate (36) which is arranged at the proximal end (34) of the pipe stub (31), wherein the first flange plate (36) can be attached to the outer surface (15) of the wall (13) of the fermenter (10) such that the test core (20) is located in the area of ​​the pipe stub (31); a second flange plate (37) which is arranged at the distal end (35) of the pipe stub (31); a cover flange (38) which can be placed gas-tight on the second flange plate (37), and a fastening element (41) which is attached to the cover flange (38) and can be connected to the test core (20). [2] Device (30) according to claim 1, further comprising a blind flange (39) which can be placed on the second flange plate (37) in a gas-tight manner instead of the cover flange (38). [3] Device (30) according to claim 1 or 2, further comprising a seal (40) arranged between the second flange plate (37) and the cover flange (38) or between the second flange plate (37) and the blind flange (39); wherein the seal (40) is preferably designed as a sealing plate and has a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or has a width in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or has a thickness in the range of 2 mm to 10 mm, preferably in the range of 4 mm to 6 mm. [4] Device (30) according to claim 3, wherein the seal (40) has a centrally arranged opening for receiving the pipe nozzle (31), the diameter of which is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm; and / or the seal (40) is made of a synthetic rubber, in particular nitrile butadiene rubber. [5] Device (30) according to one of claims 1 to 4, further comprising a threaded rod (44) and a spacer sleeve (45), wherein the fastening element (41) is attached to the cover flange (38) by means of the threaded rod (44) and the spacer sleeve (45). [6] Device (30) according to any one of claims 1 to 5, wherein the fastening element is a first fixed anchor (41). [7] Device (30) according to one of claims 1 to 6, further comprising at least one second fixing anchor (42), wherein the first flange plate (36) can be attached to the outer surface (15) of the fermenter (10) by means of the second fixing anchor (42). [8] Device (30) according to one of claims 1 to 7, further comprising at least one screw connection (43), wherein the cover flange (38) and / or the blind flange (39) are detachably connected to the second flange plate (37) by means of the screw connection (43). [9] Device (30) according to any one of claims 1 to 8, wherein the pipe stub (31) and / or the first flange plate (36) and / or the second flange plate (37) and / or the cover flange (38) and / or the blind flange (39) and / or the first fixed anchor (41) and / or the second fixed anchor (42) and / or the threaded rod (44) and / or the spacer sleeve (45) and / or the screw connection (43) are made of a stainless steel, preferably stainless steel or of alloy 1.4301 (X5CrNi18-10). [10] Device (30) according to any one of claims 1 to 9, wherein the pipe stub (31) has a diameter in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm, and / or wherein the pipe stub (31) has a length in the range of 50 mm to 150 mm, preferably in the range of 60 mm to 100 mm, and / or wherein the pipe stub (31) has a wall thickness in the range of 1 mm to 5 mm, preferably in the range of 2 mm to 3 mm. [11] Device (30) according to any one of claims 1 to 10, wherein the first flange plate (36) has a length in the range of 150 mm to 800 mm, preferably in the range of 300 mm to 400 mm, and / or wherein the first flange plate (36) has a width in the range of 150 mm to 800 mm, preferably in the range of 300 mm to 400 mm, and / or wherein the first flange plate (36) has a thickness in the range of 2 mm to 10 mm, preferably in the range of 3 mm to 6 mm. [12] Device (30) according to any one of claims 1 to 11, wherein the first flange plate (36) has a preferably centrally arranged opening for receiving the pipe stub (31), the diameter of which is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm; and / or wherein the first flange plate (36) has at least one opening, preferably four to ten openings, for receiving the second fixed anchor (42) or the second fixed anchors (42). [13] Device (30) according to any one of claims 1 to 12, wherein the second flange plate (37) has a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or wherein the second flange plate (37) has a width in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or wherein the second flange plate (37) has a thickness in the range of 2 mm to 12 mm, preferably in the range of 5 mm to 10 mm. [14] Device (30) according to any one of claims 1 to 13, wherein the second flange plate (37) has a preferably centrally arranged opening for receiving the pipe stub (31), the diameter of which is in the range of 100 mm to 650 mm, preferably in the range of 200 mm to 300 mm; and / or wherein the second flange plate (37) has at least one opening, preferably four to ten openings, for receiving the screw connection (43). [15] Device (30) according to any one of claims 1 to 14, wherein the cover flange (38) and / or the blind flange (39) have a length in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or wherein the cover flange (38) and / or the blind flange (39) have a width in the range of 150 mm to 500 mm, preferably in the range of 200 mm to 300 mm, and / or wherein the cover flange (38) and / or the blind flange (39) have a thickness in the range of 2 mm to 12 mm, preferably in the range of 5 mm to 10 mm; and / or wherein the cover flange (38) and / or the blind flange (39) have at least one opening, preferably four to ten openings, for receiving the screw connection (43). [16] Method for mounting a device (30) according to one of claims 1 to 15 on a fermenter (10) of a biogas plant, comprising the following method steps: a) Attaching the first flange plate (36) to the outer surface (15) of the fermenter (10) above the filling level (12) of a fermentation substrate (GS) in the fermentation chamber (11) of the fermenter (10); b) Performing a concrete core drilling, in particular through the pipe stub (31), and removing the core obtained by the concrete core drilling from the borehole in the wall (13) of the fermenter (10); c) Applying a coating to the borehole rim and borehole wall; d) Applying a coating to the drill core, leaving the end face of the drill core exposed which is facing the fermentation chamber (11) of the fermenter (10), to form a test drill core (20); e) Attaching the test core (20) to the cover flange (38); f) Inserting the test core (20) into the borehole while simultaneously placing the cover flange (38) onto the second flange plate (37); g) Gas-tight connection of the cover flange (38) and the second flange plate (37). [17] The method of claim 16, further comprising the following process steps: h) Checking the device (30) for leaks, preferably using a gas detector or a leak detection spray or a foaming agent; i) wherein preferably the checking of the device (30) for leaks is repeated at regular intervals, in particular monthly. [18] Method according to claim 16 or 17, characterized by , that before process step a) a lining of the fermenter (10) is removed at least in the area where the first flange plate (36) is to be attached, so that the outer surface (15) of the wall (13) is exposed. [19] Method according to any one of claims 16 to 18, characterized by, that in process step a) the first flange plate (36) is attached to the outer surface (15) of the fermenter (10) by means of the second fixing anchor (42), preferably by means of a plurality of second fixing anchors (42), further preferably by means of eight second fixing anchors (42). [20] Method according to any one of claims 16 to 19, characterized by , that in process step b) a concrete core drilling with a diameter of 50 mm to 350 mm, preferably of 100 mm to 200 mm, is carried out. [21] Method according to any one of claims 16 to 20, characterized by , that in process step c) and / or in process step d) a coating of an acid-resistant and / or fire-resistant material, preferably sodium silicate, is applied. [22] Method according to any one of claims 16 to 21, characterized by, that in process step e) the first fixed anchor (41) is placed on the end face of the test core (20) which is facing away from the fermentation chamber (11) of the fermenter (10) and is connected to the cover flange (38) by means of the threaded rod (44) and the spacer sleeve (45); wherein a distance is maintained between the test core (20) and the cover flange (38) which corresponds to the length of the pipe stub (31); wherein the distance is preferably between 50 mm and 150 mm, and further preferably between 60 mm and 100 mm. [23] Method according to any one of claims 16 to 22, characterized by , that in process step f) the seal (40) is arranged between the second flange plate (37) and the cover flange (38) and in process step g) the cover flange (38) and the second flange plate (37) are connected to each other by means of the screw connection (43) so that the device (30) is sealed gas-tight. [24] Method for taking samples (20) from a fermenter (10) of a biogas plant using a device (30) according to any one of claims 1 to 15, comprising the following method steps: i) Detaching the cover flange (38) from the second flange plate (37); ii) Extraction of the test core (20) from the borehole in the wall (13) of the fermenter (10); iii) Placing the blind flange (39) onto the second flange plate (37); iv) Gas-tight connection of blind flange (39) and second flange plate (37); v) Examination of the test core (20) outside the fermenter (10); vi) Detaching the blind flange (39) from the second flange plate (37); vii) Inserting the test core (20) into the borehole while simultaneously placing the cover flange (38) onto the second flange plate (37); viii) Gas-tight connection of the cover flange (38) and the second flange plate (37); ix) Checking the device (30) for leaks. [25] The method of claim 24, further comprising the following method step: iv.1) Checking the device (30) for leaks after process step iv), preferably using a gas detector or a leak detection spray or a foaming agent. [26] Method according to one of claims 17, 24 or 25, characterized by , that after process steps h) or i) or ix) or iv.1) leaks are sealed with a sealant.

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