Robots for suctioning mud and materials, for emptying fermentation units for biogas production

Description

[0001] The present invention relates to the field of plants for the production of biogas, which can be generated by the digestion of sludge, sewage, and organic substances in general, or can come from the fumes of slurry collection tanks containing fermentable material. It is known that such plants require ongoing management to adjust the biogas production, which comprises maintenance, and under certain circumstances, emptying and / or cleaning.

[0002] Indeed, the biogas production yield is optimized if the plant can perform an accurate and efficient anaerobic digestion but this requires, in addition to normal maintenance, a thorough cleaning (when required) of the fermenters and the anaerobic digesters to keep the digestion process efficient.

[0003] These are costly operations, which require stopping the plant and using highly specialized personnel, capable of managing the issues as for the gases and fumes of the material contained in the digesters to be cleaned.

[0004] Emptying systems are known, which provide for the suction of material by means of a suction excavator, which allows emptying even high-capacity digesters in a very short time. The suction is preferably of the dry suction type, which sucks up the settled material in the absence of water and the material is conveyed to a collection bin. With this technique, during the plant shutdown, the suction excavator - which sucks up the material through special openings - is positioned outside the digester; when most of the material has been sucked up, cleaning is completed using a mini-excavator, preferably robotic, which takes the material closer to the mouth of the suction tube with its bucket.

[0005] However, this known method requires the complete removal of the digester tank cover fabric both to use the suction excavator and to place the mini-excavator at the bottom of the digester.

[0006] The document NL8300142 A discloses a system in accordance with the preamble of claim 1.

[0007] It is one of the objects of the invention to allow the complete cleaning of the digester avoiding the need to remove the cover of the digester itself, thus reducing time and costs for cleaning and plant shutdown.

[0008] This has been achieved, according to the present invention, by the system in accordance with claim 1, which comprises using a crawler robot, preferably hydraulically operated, which is remotely controllable or driven by an operator sitting thereon, which is insertable into the digester through the so-called "manholes" pipes normally existing on the side walls of the tanks of digesters for the biogas production. Said robot is provided with a swiveling suction nose which is directly connectable to a normal suction tube of the material suction plant.

[0009] A better understanding of the invention will be achieved by means of the following detailed description and with reference to the accompanying figures, which illustrate some preferred embodiments by way of non-limiting examples.

[0010] In the drawings: figures 1 and 2 are 3D views, from the rear and front, respectively, showing the main components of a first embodiment of the crawler robot according to the present invention; figure 3 is a side view of the crawler robot in figures 1 and 2; figures 4 and 5 are a top and a bottom view of the robot in fig. 3, respectively; figures 6 and 7 are a rear and a front elevation view of the robot in fig. 3, respectively; figures 8 and 9, similar to figures 1 and 2, show the crawler robot in its "minimum" configuration, free from its removable parts to pass through a manhole with a minimum diameter of 480 mm; figure 10 is a side view of a second embodiment of the crawler robot in a complete configuration; figure 11 is an elevation view from the rear side of the crawler robot in fig. 10, in a "minimal" assembled configuration, free from the removable parts to pass through a manhole with a minimum diameter of 800 mm; figures 12 and 13 show a rear and side view, respectively, of the two upper and lower parts in which the crawler robot of fig. 10 is removable to pass through a manhole with a minimum diameter of 580 mm; figures 14 and 15, similar to fig. 11, show the crawler robot in fig. 10 with the movable nose lowered and raised, respectively; figure 16 diagrammatically shows the means for moving the nose of the crawler robot in fig. 10 in a vertical direction.

[0011] With reference to figures from 1 to 9, a first embodiment of the invention provides a crawler robot having particularly small crosswise dimensions, such as to allow it to pass through a manhole having a minimum diameter of just 48 cm.

[0012] For this purpose, the robot has a main body provided with two tracks C, as well as with a longitudinal suction pipe to the front of which a swivel nose N is fixable and to the rear of which a suction tube is fixable, whereby the system is characterized in that said main body has a particular structural configuration in which: in order to reduce the minimum distance between the two right and left tracks C, the hydraulic motors M driving them are mounted to the front and rear sides of the main body, respectively, in a mutually overturned position, with the motor body M facing inwards and the ring gear, meshing with the track C, facing outwards; the swiveling nose N is removable from the pipe present in the main body, a quick release / coupling collar being provided for this purpose; the support 1 for the hydraulic distributor 2, to control the movement means of the suction nose N and the motors M of the tracks C, is easily and quickly removable for the passage through the manhole; the support for the operator's seat, if present, is easily and quickly removable for the passage through the manhole.

[0013] In the described embodiment, the nose N consists of a fixed part (applied to the main body pipe with a quick-release collar) and a movable part: a rubber compensator joint is interposed between said fixed and movable parts.

[0014] A second particular feature of the invention is that said swiveling nose N is provided with movement means for orienting it in the desired direction, consisting of at least three hydraulic jacks 4D, 4S, 5, which are arranged at 120° (not shown) or, more preferably, are arranged at 90° relative to one another along two diameters, in particular on the right, left and upper side of the horizontal stretch of the nose N, while on the lower side a fixed-length connection / constraint element 6 with two end hinges is simply provided. In the preferred embodiment shown in the figures from 1 to 9, angular spherical joints with threaded pin are applied at the ends of each of said jacks 4D, 4S, 5, and the lower element 6 consists instead of two axial spherical joints arranged mutually in series.

[0015] In this preferred configuration, shown in figures from 1 to 9, the two hydraulic jacks, right 4D and left 4S, control the movements in the horizontal direction of the front part of the nose N, while the upper jack 5 controls the movements in the vertical direction. The lower point of the nose N, opposite to the upper jack 5, supports the joint of the movable part of the nose N during its movement.

[0016] Advantageously, with the configuration described so far, the nose N which forms the end of the suction tube can move in space in an "orbital" manner, similar to a homokinetic joint.

[0017] From the drawings and the present descriptions, it is apparent that the crawler robot according to the present invention is a very compact machine with a main body comprising a material suction pipe consisting of a tube with a nominal diameter of 21.9 cm obtained by reducing the material passage area of only 10%. Advantageously, such a reduction of the passage area occurs only in the stretch corresponding to the main body of the machine, wherein the tube is appropriately configured to facilitate the housing of the tracks C.

[0018] The compactness of the machine advantageously allows the possibility to start working in the digester to be emptied after the provision of a small maneuvering space.

[0019] According to an embodiment, not in accordance with the invention, shown in the figures from 10 to 15, a crawler robot is made in two (upper and lower) parts with rapid assembly / disassembly, to be inserted through a manhole with a minimum diameter of only 58 cm. In the example shown in figures from 10 to 15, the lower part comprising the tracks C passes through a diameter of 58 cm (or a rectangular area with 50x42 cm sides) while the upper part comprising the nose N passes through a diameter of 57 cm (or a rectangular area with 50x34 cm sides); if the machine were not divided into the above two parts, it would pass through a diameter of 80 cm.

[0020] For this purpose, the robot has a lower part provided with two tracks C to which an upper part comprising a longitudinal suction pipe, centrally articulated and provided with a front nose N' is assemblable, where said upper part is rotatably constrainable to the lower one by means of a slewing ring preferably provided with balls, the rotation of which is determined by the action of two hydraulic cylinders mounted in an opposed manner therein, which allow the rotation of an overall angle preferably of about 120° (60° rightwards and 60° leftwards), while the upper part is provided with means for varying the inclination of the front nose N' in the vertical direction by means of said central joint of the longitudinal suction pipe. Said means for varying the inclination of the nose N' are preferably hydraulically operated, e.g., by means of at least one jack, but an arc of a ring gear meshing with the pinion of a hydraulic motor could also be used.

[0021] Advantageously, the robot of this embodiment is overall very compact both in width and in length because the suction nose N' is movable in the horizontal direction by means of said slewing ring, and in the vertical direction through the means for varying the inclination of the nose N'. Preferably, the entire robot is remotely actuatable by radio control and is movable on the ground by means of said two tracks C, while the rear part of the longitudinal suction pipe, centrally articulated, is connectable at the rear to a material suction tube.

[0022] The present invention was described and illustrated with reference to a preferred embodiment but it is apparent that any person skilled in the art may make modifications and / or substitutions thereto which are functionally and / or technically equivalent, without departing from the scope of protection of the invention, which is delimited by the appended claims.

[0023] Finally, it is worth noting that the field of use of this disclosure is not advantageously limited only to the biogas plant field; the mini-robot can be used wherever there is a need to extract any type of liquid or muddy material, debris, gravel, steel mill waste, dust, from narrow places, which are difficult to access by other means, with little room for maneuver. Furthermore, the disclosure is also very useful in purification plants, where the fixtures at the bottom of the tank do not allow entering with large-sized self-propelled means.

Claims

1. A system for the suction of sludge, or debris, or sludge and debris contained in tanks or digesters for the production of biogas, which is provided with means for connecting to a suction tube of a suction system, such as a purging truck, comprising a crawler robot which is provided with remote controlling means or with driving means for an operator sitting thereon, which robot is configured to be inserted through the so-called manhole pipes normally present in the side walls of the digester tanks for the production of biogas; wherein said robot is provided with a swiveling suction nose (N, N'), which is directly connected to a suction tube of the material suction system; and wherein two parallel and longitudinal tracks (C) driven by respective motors (M) are provided, wherein said robot has a main body provided with two parallel and longitudinal tracks (C), as well as with a longitudinal suction pipe to the front of which a swiveling nose (N) is fixable and to the rear of which a suction tube is fixable, characterized in that said main body has a particular structural configuration in which: - in order to reduce the minimum distance between the two right and left tracks (C), the motors (M) driving them are mounted to the front and rear sides of the main body, respectively, in a mutually overturned position, with the motor body (M) facing inwards and a corresponding ring gear, meshing with the track (c), facing outwards; - the swiveling nose (N) is removable from the pipe present in the main body, a quick release / coupling collar being provided for this purpose; - a support (1) for a hydraulic distributor (2), to control the movement means of the suction nose (N) and the motors (M) of the tracks (C), is configured to be removed for the passage through the manhole; - a support for the operator's seat is configured to be removed for the passage through the manhole; and wherein said swiveling nose (N) is provided with movement means for orienting it in the desired direction, consisting of at least three hydraulic jacks (4D, 4S, 5) which are arranged at 120° or are arranged at 90° relative to one another along two diameters, in particular on the right, left and upper sides of a horizontal section of the nose (N), while a fixed-length connection / constraint element (6) with two end hinges is provided on the lower side.

2. A system according to the preceding claim, characterized in that said nose (N) consists of a fixed part, which is connectable to the main body pipe with a quick-release collar, and a movable part; wherein a rubber compensator joint is interposed between said fixed and movable parts.

3. A system according to claim 1 or 2, characterized in that angular spherical joints with threaded pin are applied at the ends of each of said jacks (4D, 4S, 5) arranged at 90° and the lower element (6) consists of two axial spherical joints arranged mutually in series.

4. A system according to the preceding claim, characterized in that the two right (4D) and left (4S) hydraulic jacks are configured to control the movements in the horizontal direction of the front part of the nose (N), while the upper jack (5) is configured to control the movements in the vertical direction; wherein the lower point of the nose (N), opposite to the upper jack (5), is configured to support the joint of the movable part of the nose (N) during its movement.

5. A system according to one of the preceding claims, characterized in that said nose (N), which forms the front end of the suction tube connected to the robot, is movable in space in an orbital manner, similar to a homokinetic joint.

6. A system according to one of the preceding claims, characterized in that said crawler robot is a compact machine with a main body comprising a material suction pipe consisting of a tube with a nominal diameter of 21.9 cm made by providing for a reduction of the material passage area of only 10%; wherein such a reduction of the passage area is provided for only in the section corresponding to the main body of the machine, where the tube is conveniently configured to facilitate the housing of the tracks (C).