A cleaning device, a wastewater cleaning system and wastewater cleaning method

Abstract

A cleaning device (1) comprising a frame (3) and a tubular element (2) rotatably supported by the frame (3) and including an outer surface (2a). To rotate the tubular element (2) relative to the frame (3), a driving unit (8) is provided. A plurality of catching elements (9,10,19,20) extend outwardly through corresponding openings (11,12) in the outer surface (2a) of the tubular element (2). A reciprocating mechanism (21,24) is provided to move the plurality of catching elements (9,10,19,20) during rotation of the tubular element (2) between an outward position and an inward position in which free ends of the plurality of catching elements (9,10,19,20) are at a larger distance from the outer surface (2a) of the tubular element (2) in the outward position than in the inward position. The invention also relates to a corresponding wastewater system and a wastewater cleaning method.

Description

[0001] TITLE OF THE INVENTION

[0002] A cleaning device, a wastewater cleaning system, and wastewater cleaning method

[0003] BACKGROUND OF THE INVENTION

[0004] The invention relates to the cleaning of a liquid body, in particular a liquid flow, for instance wastewater, such as sewage.

[0005] Sewage is wastewater, typically household wastewater that is produced by a community of people. A sewage system (also called sewerage) is the infrastructure used to convey sewage from the point of production to the point of treatment or discharge and includes pipes which are referred to as sewers. A sewage system may alternatively, or additionally, be used to convey surface runoff such as stormwater, meltwater and rainwater.

[0006] Sewage systems' main advantage is that they contribute to public health by removing human waste. An increasing problem for sewage systems are sewer obstructions and / or damage to sewer infrastructure, such as pumping units, caused by an increasing amount of relatively large articles that are introduced into the sewage system but for which the sewage system is not intended or designed, such as tissue, sanitary towels, plastic products, ropes etc. Similar problems may be present in other wastewater flows and / or liquid bodies.

[0007] Currently, grids arranged in the sewage system are used to prevent the articles from reaching pumping units but with the increasing amount of articles, the articles upstream of the grids cause obstructions themselves and have to be cleaned / cleared frequently. Another disadvantage of the grids is that flexible articles such as towels are difficult to capture using a grid.

[0008] SUMMARY OF THE INVENTION

[0009] In view of the above it is an object of the invention to provide an improved way of cleaning a liquid body to reduce obstructions and / or reduce the risk of damage to infrastructure downstream of the cleaning. According to a first aspect of the invention, there is provided a cleaning device comprising: a frame, a tubular element rotatably supported by the frame and including an outer surface, a driving unit to rotate the tubular element relative to the frame about a rotation axis, a plurality of catching elements extending outwardly through corresponding openings in the outer surface of the tubular element, and a reciprocating mechanism to move the plurality of catching elements during rotation of the tubular element between an outward position and an inward position in which free ends of the plurality of catching elements are at a larger distance from the outer surface of the tubular element in the outward position than in the inward position.

[0010] A benefit of the cleaning device according to the first aspect of the invention is that the rotating tubular element with the plurality of catching elements can be arranged in a liquid body, in particular a liquid flow, such as a wastewater or sewage to catch debris and / or articles in the liquid body and move them easily out of the liquid body thereby cleaning the liquid body and reducing the risks of obstructions or damage downstream of the cleaning device.

[0011] By reciprocating the plurality of catching elements between an outward position and an inward position, the tubular element holding the plurality of catching elements can be arranged eccentrically in a liquid flow allowing to remove articles from the liquid flow mainly at one side of the tubular element which makes it easier to remove the articles from the liquid flow compared to the situation in which articles have to be removed at both sides of the tubular element.

[0012] In an embodiment, the rotation axis of the tubular element is intended to be oriented substantially horizontally in use, i.e. having an angle relative to the horizontal that is at most 30 degrees, preferably at most 20 degrees, more preferably at most 15 degrees and most preferably at most 15 degrees.

[0013] In an embodiment, the free ends of the plurality of catching elements are flush with or recessed with respect to the outer surface of the tubular element in the inward position. An advantage thereof is that the cleaning device can be arranged extremely eccentrically in a liquid flow so that the chance of articles inadvertently passing the cleaning device at the side where the catching elements are at their inward position is minimal. The flush / recessed inward position also allows to remove any dirt and / or articles sticking to the catching elements and / or the outer surface of the tubular element.

[0014] In an embodiment, the outer surface of the tubular element is closed except for the openings through which the catching elements extend. This prevents dirt and / or articles from entering the interior space of the tubular element.

[0015] In an embodiment, at least one end of the tubular element is closed to prevent dirt and / or articles from entering the interior space of the tubular element via said at least one end. Preferably both ends of the tubular element are closed. This may also prevent that the dirt and / or articles pass through the cleaning device without being removed from the liquid flow.

[0016] In an embodiment, the tubular element is configured to allow liquid to enter the interior space of the tubular element. The presence of liquid may have the advantage that the mechanism can be kept clean and / or lubricated and reduces the buoyancy forces applied to the tubular element compared to a water-tight tubular element positioned in the liquid body.

[0017] In an embodiment, the plurality of catching elements include bars or rods, preferably cylindrical bars or rods.

[0018] In an embodiment, the tubular element is a cylindrical element and may alternatively be referred to as drum. In an embodiment, the openings in the outer surface of the tubular element through which the plurality of catching elements extend guidingly engage with a corresponding catching element, preferably the full circumference of the openings guidingly engage with the catching elements extending through the openings. An advantage thereof may be that dirt, debris or articles attached or sticking to the catching element can be pushed off the catching elements by the outer surface when moving from the outward position to the inward position.

[0019] In an embodiment, the outward position of the plurality of catching elements corresponds to a first angular position of the tubular element in which the plurality of catching elements are in a substantially horizontal orientation. Preferably, the cleaning device is arranged in a liquid body such that the substantial horizontal orientation of the catching element is at or near the surface of the liquid body. An advantage thereof may be that the chance of successfully removing articles from a liquid body is higher as the reach of the catching elements is maximal when the catching elements leave the liquid body.

[0020] In an embodiment, the cleaning device is configured such that the rotational direction of the tubular element is such that the catching elements move upwards when reaching the outward position.

[0021] In an embodiment, the inward position of the plurality of catching elements corresponds to a second angular position of the tubular element that has a substantially 180 degrees difference with the first angular position. In this way, the movement of the catching elements, namely from inward position to outward position and back to the inward position corresponds to a single rotation of the tubular element and may be represented by a sine function.

[0022] In an embodiment, the plurality of catching elements are distributed over the outer surface of the tubular element in a direction parallel to the rotation axis, preferably at a first side of the tubular element, e.g. in a straight line having a predetermined distance between adjacent catching elements.

[0023] In an embodiment, the plurality of catching elements include a first set of catching elements distributed over the outer surface of the tubular element in a direction parallel to the rotation axis at a first side of the tubular element, and a second set of catching elements distributed over the outer surface of the tubular element in a direction parallel to the rotation axis at a second side of the tubular element, and wherein preferably the second side is opposite the first side.

[0024] With only one set of catching elements, articles can be removed once during a single rotation of the tubular element. Now that there is a second set of catching elements, articles can be removed at least twice during a single rotation of the tubular element.

[0025] This may be extended to a third and even a fourth set of catching elements or more, so that in one embodiment, the plurality of catching elements include a third set of catching elements distributed over the outer surface of the tubular element in a direction parallel to the rotation axis at a third side of the tubular element different from the first and second side, and in a further embodiment, the plurality of catching elements include a fourth set of catching elements distributed over the outer surface of the tubular element in a direction parallel to the rotation axis at a fourth side of the tubular element, preferably opposite the third side of the tubular element.

[0026] With two sets of catching element, the angle between the two sets may be 180 degrees. With three sets of catching elements, the angle between two adjacent sets may be 120 degrees, and with four sets of catching elements, the angle between two adjacent sets may be 90 degrees. This logic may be extended when additional sets of catching elements are provided. Additional sets of catching elements are beneficial with increasing size of the cleaning device

[0027] In an embodiment, each catching element of the first set of catching elements is coupled to a respective catching element of the second set of catching elements. In an embodiment, each catching element of the third set of catching elements is coupled to a respective catching element of the fourth set of catching elements.

[0028] The same may apply for any additional pair of sets of catching element.

[0029] In an embodiment, a length of the tubular element is at least 5 cm, preferably at least 10 cm, more preferably at least 15 cm, and most preferably at least 25 cm. However, it is explicitly noted that these values are not meant to indicate that larger cleaning devices are not feasible. However, a relatively compact device may have advantages, but a minimal length is preferred to increase the chances of success to remove dirt, debris and / or articles from the liquid body.

[0030] In an embodiment, seen in a direction parallel to the horizontal rotation, at least three, preferably at least four, more preferably at least five and most preferably at least six catching elements are distributed, preferably evenly, over a length of the tubular element. When the cleaning device includes two or more sets of catching elements as described above, this feature may apply to each set of catching elements.

[0031] In an embodiment, seen in a direction parallel to the horizontal rotation, a distance between adjacent catching elements is at most 25 cm, preferably at most 15 cm, more preferably at most 10 cm, even more preferably at most 8 cm, most preferably at most 5 cm, for instance about 2 cm.

[0032] In an embodiment, the frame includes a lifting member at an upper side of the cleaning device to engage with a lifting device allowing to lower and lift the cleaning device in and out of a tube element, e.g. a sewer element, for installation and / or maintenance purposes.

[0033] In an embodiment, the frame is configured to engage with a tube element such as a sewer element, e.g. a mainly cyclind rica lly shaped sewer element, for supporting the cleaning device from the tube element. In an embodiment, the cleaning device includes an anti-theft sensor, and a communication device to communicate with an external device. The anti-theft sensor may for instance be configured to determine whether the cleaning device is in a desired position and the communication device may be configured to communicate a signal when the cleaning device is removed or moved away from this desired position. The anti-theft sensor may in a simple configuration be able to determine whether the cleaning device is present in or absent from the desired position, but may in a more complex configuration be able to determine a (geographical) location of the cleaning device. The sensor may include a gps sensor allowing for instance tracking of the position of the cleaning device.

[0034] The anti-theft sensor may also be configured to determine the structural integrity of at least a portion of the cleaning device. The sensor may for instance be configured to determine whether a housing is opened or not, or if two parts of the cleaning device are still in a desired relative orientation / position.

[0035] The communication device may for instance be configured to provide status updates on power usage of the driving unit and / or rotational speed of the tubular element. A high power usage may for instance indicate an obstruction or malfunction of the cleaning device and measures may be taken prior to the driving unit or other components being damaged.

[0036] According to a second aspect of the invention, there is provided a wastewater system comprising: a tube element having an inlet for wastewater and an outlet for wastewater defining a flow direction from the inlet to the outlet, and a cleaning device according to the first aspect of the invention arranged at least partially in the tube element such that the plurality of catching elements move through the wastewater in a moving range in between the inward and outward position when moving towards the outward position. In an embodiment, the rotation axis of the tubular element of the cleaning device is substantially parallel to the flow direction defined by the tube element.

[0037] In an embodiment, the rotation axis of the tubular element of the cleaning device is substantially perpendicular to the flow direction defined by the tube element. Preferably, the tubular element is configured to rotate such that when the catching elements move through the wastewater, i.e. in the moving range in between the inward and outward position when moving towards the outward position, they move in a direction opposite the flow direction.

[0038] In an embodiment, the tube element has an open section, wherein the tubular element is arranged adjacent to an upper edge of the open section of the tube element, wherein the catching elements extend away from the upper edge of the open section in the outward position and towards the upper edge of the open section in the inward position.

[0039] In an embodiment, the wastewater system further includes a reception container arranged next to the tube element to receive articles removed from a wastewater flow in the tube element by the cleaning device.

[0040] In an embodiment, when the catching elements move through the wastewater, a distance between free ends of the catching elements and the tube element is at most 10% of a diameter of the tube element, preferably at most 7% of the diameter of the tube element, more preferably at most 5% of the diameter of the tube element, even more preferably at most 4% of the diameter of the tube element, and most preferably at most 3% of the diameter of the tube element, e.g. about 1% or 2% of the diameter of the tube element. Alternatively, or additionally, when the catching elements move through the wastewater, a distance between free ends of the catching elements and the tube element is at most 5 cm, preferably at most 4 cm, more preferably at most 3 cm, even more preferably at least 2 cm, and most preferably at most 1 cm, for instance at most 0.5 cm.

[0041] In an embodiment, the frame of the cleaning device is in engagement, e.g. connected, to the tube element such that the tube element supports the cleaning device. In an embodiment, the frame of the cleaning device includes a lifting member at an upper side of the cleaning device to engage with a lifting device allowing to lower and lift the cleaning device in and out of a tube element for installation and / or maintenance purposes.

[0042] In an embodiment, the wastewater system is a sewage system and the tube element is a sewer element.

[0043] In an embodiment, a scraper or knife is provided, e.g. forming or extending from an upper edge of the tube element, to be positioned close to or in engagement with the tubular element of the cleaning device at a location corresponding to the inward position of the catching elements to remove dirt and / or articles from the tubular element and guide them away from the tube element, e.g. into the reception container.

[0044] In an embodiment, the wastewater system includes a sensor system to measure the presence of dirt, debris and / or articles in the wastewater upstream of the cleaning device.

[0045] In an embodiment, the wastewater system includes a control system to operate the cleaning device in dependency of signals of the sensor system.

[0046] In an embodiment, the control system is configured to rotate the tubular element when the sensor system indicates debris and / or articles in the wastewater upstream of the cleaning device and to stop rotation of the tubular element when the sensor system does not indicate debris and / or articles to be removed. Instead of on / off as described above, it is alternatively possible that the control system changes rotation speed, so for instance 100% of a desired rotation speed when the sensor system indicates debris and / or articles in the wastewater upstream of the cleaning device and 25-50% of a desired rotation speed when the sensor system does not indicate debris and / or articles to be removed. In an embodiment, the control system is configured to temporary rotate the tubular element after a predetermined time period that the tubular element hasn't rotated even when the sensor system does not indicate debris and / or articles to be removed. An advantage thereof may be that the chance of the cleaning device getting stuck or clogged is reduced as the cleaning device or components thereof is / are regularly wetted / cleaned.

[0047] In an embodiment, the sensor system and / or control system may be configured to use machine learning to improve the upstream recognition of debris and / or articles. In such a case, a sensor may be provided to determine the dirt, debris and / or articles that have been removed from the wastewater by the cleaning device to provide feedback to the dirt, debris and / or articles detected upstream by another sensor.

[0048] In an embodiment, a sensor may be provided to determine a filling level of the reception container. The control system may then for instance be configured to stop the cleaning device to prevent an overflow of the reception container. Alternatively, or additionally, the control system may be configured to output a corresponding signal as an indication that the reception container needs to be emptied or replaced. The signal may be sent early, i.e. before the maximum filling level is reached, to provide sufficient time for emptying or replacing the reception container to minimize downtime of the cleaning device.

[0049] According to a third aspect of the invention, there is provided a method for cleaning wastewater flowing through a tube element, said method comprising the step of rotating a tubular element eccentrically through the wastewater along with a plurality of catching elements, which catching elements during rotation of the tubular element reciprocate between an outward position at one side of the tube element and an inward position at an opposite side of the tube element to remove articles from the wastewater using the catching elements.

[0050] In an embodiment, in the inward position of the catching elements the free ends of the plurality of catching elements are flush with or recessed with respect to the outer surface of the tubular element, and wherein a scraper or knife is arranged close to or in engagement with the tubular element at the location where the catching elements are in the inward position to remove any debris or articles from the tubular element.

[0051] To avoid unduly repetition of embodiment and / or features, it is explicitly noted here that embodiments and / or features described in relation to one aspect of the invention may readily apply to other aspects as well. It is within the skilled person's reach to amend language accordingly. For instance, embodiments and / or features described in relation to a method, typically using active language, may be described for a corresponding device or system using passive language, e.g. using language like "configured to [active language]", and the other way around.

[0052] BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The invention will now be described in a non-limiting way by reference to the accompanying drawings in which like parts are indicated by like reference symbols, and in which:

[0054] Fig. 1 schematically depicts a perspective view of a sewage system according to an embodiment of the invention,

[0055] Fig. 2 schematically depicts a perspective exploded view of a rotatale drum of the sewage system of Fig. 1,

[0056] Fig. 3 schematically depicts a perspective view of a cathing unit associated with the rotatable drum of Fig. 2,

[0057] Fig. 4 schematically depicts a perspective view of a pair of catching pins of the catching unit of Fig. 3,

[0058] Fig. 5A schematically depicts a cross-sectional view of the rotatable drum of Fig. 1, in a first operational position,

[0059] Fig. 5B schematically depicts a cross-sectional view of the rotatable drum of Fig. 1, in a second operational position,

[0060] Fig. 5C schematically depicts a cross-sectional view of the rotatable drum of Fig. 1, in a third operational position,

[0061] Fig. 5D schematically depicts a cross-sectional view of the rotatable drum of Fig. 1, in a fourth operational position, Fig. 5E schematically depicts a cross-sectional view of the rotatable drum of Fig. 1, in a fifth operational position, and

[0062] Fig. 5F schematically depicts a cross-sectional view of the rotatable drum of Fig. 1, in a sixth operational position

[0063] DETAILED DESCRIPTION OF THE INVENTION

[0064] Fig. 1 schematically depicts a perspective view of a sewage system according to an embodiment of the invention. The sewage system is an example of a wastewater system according to the second aspect of the invention. The sewage system includes a sewer tube 4 and a sewage cleaning device 1 for cleaning the sewage flowing through the sewer tube 4. The sewage cleaning device 1 is an example of a cleaning device according to the first aspect of the invention.

[0065] The sewer tube 4 is an example of a tube element and includes an open section 4a allowing to remove articles and / or debris from the sewage flowing through the sewer tube 4. The open section 4a of the sewer tube 4 may be arranged in inspection pits. In an embodiment, the sewage cleaning device 1 is retrofitted into an existing sewer tube 4 that initially was configured for inspection only and with the presence of the sewage cleaning device 1 is now also configured for cleaning. In another embodiment, the sewage system is initially used for cleaning only, but may additionally also be used for inspection purposes, especially when the sewage cleaning device 1 can relatively easily be removed from the sewer tube 4, e.g. for maintenance of the sewage cleaning device 1. It is also possible that the sewage system is not used for inspection.

[0066] The sewage cleaning device 1 is provided with a rotatable drum 2 and a frame 3 for carrying the rotatable drum 2 in the open section 4a of the sewer tube 4. As shown, the tube of the sewer 4 is partially open i.e. provided without a top portion 4' forming an open channel profile so as to make the interior 5 of the tube 4 accessible e.g. for inspection and / or cleaning purposes. Adjacent upstream and downstream tube sections 4b, c are closed i.e. provided with a top portion 4' forming a closed wall contour around the interior 5 of the tube 4. The open section 4a of the sewer tube 4 is also referred to as inspection tube 4a. Here, the tube 4a has an upper edge 6 at the left and an upper edge 7 at the right. The terms "left" and "right" are in this case used in relation to Fig. 1 only.

[0067] Tube section 4b may alternatively be referred to as inlet of the sewer tube 4 and tube section 4c may alternatively be referred to as outlet of the sewer tube 4, such that a flow direction FD may be defined as indicated by the corresponding arrow from inlet to outlet of the sewer tube.

[0068] The frame 3 of the sewage cleaning device 1 is mounted such that the rotatable drum 2 is placed in the inspection tube 4a such that the rotatable drum 2 is substantially parallel and eccentric relative to the sewer tube 4. Further, the rotatable drum 2 is located adjacent to the left upper edge 6 of the inspection tube 4a. Optionally, the frame 3 is provided with a movable connection structure such as a rail structure for connecting the rotatable drum 2 to the frame 3 such that the rotatable drum 2 can be precisely located at a desired location, e.g. by shifting the drum 2 relative to the frame 3.

[0069] In the shown embodiment, the rotatable drum 2 has a body axis B, and the sewer tube 4 has a longitudinal axis A. The body axis B and the longitudinal axis A are mainly parallel to each other. Further, in the shown embodiment, the body axis B of the rotatable drum and the upper edge 6 of the inspection tube 4a are located at substantially the same height level to optimize a throw out procedure as described in more detail below. In this context it is already mentioned that, in principle, the rotatable drum 2 can be located somewhat higher or lower relative to the upper edge 6 of the inspection tube 4a.

[0070] The sewage cleaning device 1 as shown in Fig. 1 also has a driving mechanism, i.e. a driving unit, including an electric motor 8 for rotating the rotatable drum 2 along its body axis B thus acting as horizontal rotation axis. The driving mechanism is preferably arranged downstream of the sewage cleaning device 1, which side will be the "clean" side of the sewage cleaning device as dirt, debris and / or articles are removed upstream of the driving mechanism and thus damage to the driving mechanism will be minimized. Further, the device 1 also has a catching unit associated with the rotatable drum 2 for catching non-degradable articles such as tissue, sanitary towels, plastic products, ropes etc. from the interior 5 of the sewer tube 4 where the sewage flows.

[0071] The catching unit includes several sets of catching elements, in this case catching pins 9, 10 traversing corresponding openings 11, 12 in the rotatable drum 2, in particular in an exterior wall, i.e. outer surface, of the drum 2. The catching pins 9, 10 are allowed to reciprocate, or move to and from, or back and forth through said openings 11, 12. The catching unit also includes a reciprocating mechanism arranged for alternatingly driving the sets of catching pins 9, 10 between an outward position and an inward position, relative to the rotatable drum 2. In particular, the reciprocating mechanism alternatingly drives the pins 9, 10, during rotation of the drum 2, to an outward position when the pins 9, 10 are directed away from the upper edge 6 of the inspection tube 4a, in the embodiment shown in Fig. 1 to the right transverse direction RTD, and back to an inward position when the pins 9, 10 are directed towards the upper edge 6 of the inspection tube 4a, in the embodiment shown in Fig. 1 to the left transverse direction LTD, opposite to the right transverse direction RTD.

[0072] Figure 2 shows a schematic perspective exploded view of a rotatable drum 2 of the sewage cleaning device 1 shown in Fig. 1. The rotatable drum 2, which may alternatively be referred to as tubular element 2, includes an exterior wall 2a, longitudinal end walls 2b, b' closing off the interior of the rotatable drum 2, and bearing elements 2c, c' forming a connection of the drum 2 to the frame 3. In the shown embodiment, the driving mechanism for rotating the rotatable drum 2 along its body axis B includes a driving axle 13 protruding through the end wall 2b, coupled to the electric motor 8 and connected to a gear wheel or sprocket 14 engaging with an inner gear 15 provided at the inner surface 16 of the exterior drum wall 2a. Upon rotating the driving axle 13, via the electric motor 8, the gear wheel 14 causes the drum 2 to rotate, via its inner gear 15.

[0073] In this context, it is noted that the driving mechanism can be implemented, in principle, in another manner, e.g. via a central axle, for causing the drum 2 to rotate and simultaneously driving the reciprocating mechanism. Further, the driving power can be delivered using an electric motor 8 that is mounted to the frame, or using another device, e.g. a portable power tool removably connected to the driving axle 13 of the driving mechanism.

[0074] As shown in Fig. 2, the catching unit includes several sets of catching pins 9, 10, 19 also referring to the description in relation to Fig. 3 describing the operation of the catching pins in more detail.

[0075] Further, as shown in Fig. 2, the reciprocating mechanism includes two additional gear wheels 17, 18 rotatably coupled, via bearings in the corresponding longitudinal end walls 2b, b', to the rotatable drum 2. The two additional gear wheels 17, 18 are fixedly coupled to a crankshaft that is located inside the rotatable drum 2 and interposed between said gear wheels 17, 18. Also the crankshaft gear wheels 17, 18 engage with corresponding inner gears 15 provided at the inner surface 16 of the exterior drum wall 2a. During rotation of the drum 2, also the crankshaft gear wheels 17, 18, and the crankshaft itself, are forced to rotate. However, the crankshaft is blocked against a transverse movement relative to the body axis B of the rotatable drum 2. The crankshaft converts a rotational motion into a reciprocating motion.

[0076] Figure 3 shows a schematic perspective exploded view of a catching unit associated with the rotatable drum 2 shown in Fig. 2. The catching unit includes several sets of catching pins 9, 10, 19, 20 and the reciprocating mechanism is configured for alternatingly driving the pins 19, 10, 19, 20 between an outward position and an inward position, relative to the rotatable drum 2. The crankshaft 21 fixedly coupled to its gear wheels 17, 18, via subaxles 22, 23, has a corrugated contour including a set of cams 24 coupled to the sets of catching pins 9, 10, 19, 20.

[0077] In the shown embodiment, the cams 24 have opposite end portions 25a, b that are alternatingly connected to each other. Here, a first end portion 25a of a first cam 24a is connected, via a first coupling axle 26, to a first end portion 25a of a subsequent, second cam 24b. Further, a second end portion 25b of the second cam 24b is connected, via a second coupling axle 27, to a second end portion 25b of a subsequent, third cam 24c. In the above manner, first end portions 25a are connected to each other, via first coupling axles 26, and second end portions 25b are connected to each other, via second coupling axles 27, however such that the first and second coupling axles 26, 27 alternate each other, forming a regular corrugated pattern. In this pattern, the first coupling axles 26 are opposite to the second coupling axles 27.

[0078] In the shown embodiment, the catching unit includes a first set of catching pins 9 and a second set of catching pins 19, coupled to cams 24 of the crankshaft 21, wherein pins of the first set of pins 9 are mainly aligned with and directed opposite to corresponding pins of the second set of pins 19, having the crankshaft 21 therebetween. Here, corresponding pins of the first and second sets of pins 9, 19 are coupled to the same corresponding cams 24 of the crankshaft 21, as described in more detail referring to Fig. 4.

[0079] Further, in the shown embodiment, the catching unit includes a third set of catching pins 10 and a fourth set of catching pins 20 coupled to cams 24 of the crankshaft 21, wherein pins of the third set of pins 10 are mainly aligned with and directed opposite to corresponding pins of the fourth set of pins 20, and wherein the pins of the third and fourth sets of pins 10, 20 are oriented mainly transverse to the pins of the first and second sets of pins 9, 19.

[0080] Figure 4 shows a schematic perspective view of a pair of catching pins 9, 19 of the catching unit shown in Fig. 3. Each of the pins 9, 19 has a proximal end 9a, 19a and a distal end 9b, 19b. As also shown, the catching unit includes a coupling element or crankpin 28 having an annular shaped piece 29 with surrounded aperture 30 receiving, via a bearing 31, a first coupling axle 27. The coupling element 28 also has coupling pins 32, 33 arranged at mutually opposite sides on the annular shaped piece 29 for connecting with corresponding proximal ends 9a, 19a of the pair of catching pins 9, 19.

[0081] The shown upper pin 9 of the first set of pins 9 in Fig. 4 forms, together with the shown lower pin 19 of the second set of pins 19 a pair of pins 9, 19 that are coupled to the same cam, via the shown coupling element 28. The pair of pins 9, 19 are coupled to the same first coupling axle 27. The first coupling axles 27 shown in Fig. 3 are each provided with a coupling element 28 as shown in Fig. 4 for coupling to the first and second sets of pins 9, 19. Then, all pairs of pins 9, 19 of the first and second sets of pins 9, 19 are coupled to the same corresponding cam 24. Also, all pairs of pins 9, 19 of the first and second sets of pins 9, 19 are coupled to the same corresponding first coupling axle 27.

[0082] Similarly, also the second coupling axles 28 show in Fig. 3 are each provided with a coupling element 28 as shown in Fig. 4 for coupling to the third and second sets of pins 10, 20. Then, all pairs of pins 10, 20 of the third and fourth sets of pins 10, 20 are coupled to the same corresponding cam 24. Also, all pairs of pins 10, 20 of the first and second sets of pins 10, 20 are coupled to the same corresponding second coupling axle 28.

[0083] By providing the catching unit with a reciprocating mechanism as described above, the pins 9, 10, 19, 20 are alternatingly driven between an outward position and an inward position, relative to the rotatable drum 2, during rotation of the drum 2. As shown in more detail referring to Fig. 5, in the outward position, a main portion of a catching pin 9, 10, 19, 20 extends outside the rotatable drum, while, in the inward position, at least the main portion of the catching pin 9, 10, 19, 20 is withdrawn inside the rotatable drum 2.

[0084] Figure 5A shows a schematic cross-sectional view of the rotatable drum 2 shown in Fig. 2, in a first operational position. Here, a single pin 9, 10, 19, 20 of the first, second, third and fourth sets of pins is shown. Also, a single cam 24 of the crankshaft 21 is shown, the cam having a first coupling axle 27 and a second coupling axle 28. As described above referring to Fig. 3, the pin of the first and second sets 9, 19 are coupled to the first coupling axle 27, while the pin of the third and fourth sets 10, 20 are coupled to the second coupling axle 28. In the shown position, the first pin 9 is completely withdrawn in the drum 2, while the second pin is in the outward position, protruding from the drum 2 outwardly. The third and fourth pins 10, 20 are in a position between the inward and outward position.

[0085] Fig. 5A further clearly shows that the edge 6 may form a scraper or knife arranged close to or in engagement with the tubular element 2 at a location where the catching elements 20 are in the inward position. Because the catching elements 20 are preferably flush or more preferably recessed with respect to the outer surface of the tubular element, the catching elements and the scraper or knife 6 do not interfere with each other, but debris and / or articles on the tubular element will be removed from the tubular element by the scraper or knife and moved to a reception container 50 as described below in more detail. For simplicity reasons, the reception container 50 is only shown in Fig. 5F.

[0086] Figure 5B shows a schematic cross-sectional view of the rotatable drum shown in Fig. 2, in a second operational position, wherein the crankshaft 21 has pivoted in a clockwise direction CD over circa 90 degrees, compared to the first operational position. Now, the fourth pin 20 catches an article 30 in the inspection tube 4a. The drum 2 has now pivoted over circa 45 degrees, also in the clockwise direction CD.

[0087] Figure 5C shows a schematic cross-sectional view of the rotatable drum 2 shown in Fig. 2, in a third operational position, wherein the crankshaft 21 has pivoted in a clockwise direction CD over circa 180 degrees, compared to the first operational position, and the drum 2 has pivoted over circa 90 degrees, in the clockwise direction CD. Now, the third pin 10 has reached the inward position avoiding a contact with the upper edge 6 of the inspection tube 4a.

[0088] Figure 5D shows a schematic cross-sectional view of the rotatable drum 2 shown in Fig. 2, in a fourth operational position, wherein the crankshaft 21 has pivoted in a clockwise direction CD over circa 270 degrees, compared to the first operational position, and the drum 2 has pivoted over circa 135 degrees, in the clockwise direction CD. The fourth pin 20 catches the article 30 upwardly from the inspection tube 4a.

[0089] Fig. 5E shows a schematic cross-sectional view of the rotatable drum 2 shown in Fig. 2, in a fifth operational position, wherein the crankshaft 21 has pivoted in a clockwise direction CD over circa 360 degrees, compared to the first operational position, and the drum 2 has pivoted over circa 180 degrees, in the clockwise direction CD. The second pin 19 has reached the inward position avoiding a contact with the upper edge 6 of the inspection tube 4a.

[0090] Fig. 5F shows a schematic cross-sectional view of the rotatable drum 2 shown in Fig. 2, in a sixth operational position. Here, the crankshaft 21 has pivoted in a clockwise direction CD over another circa 180 degrees, compared to the fifth position, and the drum 2 has pivoted over another circa 90 degrees, in the clockwise direction CD. The fourth pin 20 has reached the inward position avoiding a contact with the upper edge 6 of the inspection tube 4a. Now, the fourth pin 20 also loses contact with the caught article 30 that is ejected or thrown out, the upper edge 6 of the inspection tube 4a serving as a separating knife contributing in the separation of the article 30 from the catching pin 20.

[0091] From the above description it follows that, in the shown embodiment, the gear coupling of the crankshaft 21 relative to the drum 2 is designed such that a rotation speed of the crankshaft 21 is twice a rotation speed of the rotatable drum 2.

[0092] The catching pins 9, 10, 19, 20 made be mainly uniform in thickness, longitudinal dimension and material. Preferably, a stiffness of the catching pins 9, 10, 19, 20 is chosen such that its stiffness is low enough to not cause typical articles to be removed from the interior 5 of the sewer tube 4 any severe damage to said pins, while, on the other hand, said stiffness is high enough to enable said pins to catch said articles and to throw them out of the inspection tube 4a.

[0093] It is noted that, as an example of possible alternative embodiments, the rotatable drum 2 can be placed adjacent to the left upper edge 6 of the inspection tube 4a. However, alternatively, the rotatable drum 2 can be placed at another location in the inspection tube 4a, e.g. at the right upper edge 7. Then, the catching unit may be modified such that the catching pins reciprocate between an outward position at the left of the rotatable drum 2 and an inward position at the right of the rotatable drum 2.

[0094] Alternatively, the invention may be summarized by the following clauses: 1. A sewer cleaning device, comprising a rotatable drum and a frame for carrying the rotatable drum in an open section of a sewer tube, the rotatable drum being placed in a mainly eccentric, parallel position relative to the sewer tube and adjacent to an upper edge of the open section of the sewer tube, the device further comprising a catching unit associated with the rotatable drum, the catching unit including a set of catching pins traversing corresponding apertures in the rotatable drum and a reciprocating mechanism arranged for alternatingly driving the set of catching pins to an outward position when the set of catching pins are directed away from the upper edge of the open section of the sewer, and to an inward position when the set of catching pins are directed towards the upper edge of the open section of the sewer.

[0095] 2. A sewer cleaning device according to clause 1, wherein the reciprocating mechanism is provided with a crankshaft having a set of cams coupled to the set of catching pins.

[0096] 3. A sewer cleaning device according to clause 2, wherein the crankshaft is rotatably coupled to the rotatable drum, and preferably located inside the rotatable drum.

[0097] 4. A sewer cleaning device according to any of the preceding clauses, wherein, in the outward position, a main portion of the catching pin extends outside the rotatable drum, and wherein, in the inward position, at least the main portion of the catching pin is withdrawn inside the rotatable drum.

[0098] 5. A sewer cleaning device according to any of the preceding clauses, comprising a first set of catching pins and a second set of catching pins, coupled to cams of the crankshaft, wherein pins of the first set of pins are mainly aligned with and directed opposite to corresponding pins of the second set of pins.

[0099] 6. A sewer cleaning device according to clause 5, wherein corresponding pins of the first and second sets of pins are coupled to the same corresponding cams of the crankshaft.

[0100] 7. A sewer cleaning device according to clause 5 or 6, further comprising a third set of catching pins and a fourth set of catching pins coupled to cams of the crankshaft, wherein pins of the third set of pins are mainly aligned with and directed opposite to corresponding pins of the fourth set of pins, and wherein the pins of the third and fourth sets of pins are oriented mainly transverse to the pins of the first and second sets of pins.

[0101] 8. A sewer cleaning device according to any of the preceding clauses, wherein the rotatable drum has a body axis mainly in parallel to a longitudinal axis of the sewer tube.

[0102] 9. A sewer cleaning device according to clause 8, wherein the crankshaft is blocked against a transverse movement relative to the body axis of the rotatable drum.

[0103] 10. A sewer cleaning device according to any of the preceding clauses, wherein a rotation speed of the crankshaft is twice a rotation speed of the rotatable drum.

[0104] 11. A sewer cleaning device according to any of the preceding clauses, wherein the body axis of the rotatable drum and the upper edge of the open section of the sewer tube are located at substantially the same height level.

[0105] 12. A sewer cleaning device according to any of the preceding clauses, further comprising a driving mechanism for rotating the rotatable drum.

[0106] It is further mentioned, that although the drawings relate to the cleaning of sewage and a sewage system, the invention according to the first, second and third aspect of the invention may also be used in other applications and situations. Any wastewater flow like sewage can be cleaned using a cleaning device, wastewater system or method according to the invention. It is even possible to attach the cleaning device to a vessel and move this vessel with cleaning device through a liquid body to remove articles from the liquid body into the vessel or other reception container. In such a case, it may be preferred that the catching elements extend away from the vessel in the outward position. It may also be preferred that the rotation axis of the tubular element in such a situation is substantially perpendicular to a forward moving direction of the vessel.

Claims

C L A I M S1. A cleaning device comprising: a frame, a tubular element rotatably supported by the frame and including an outer surface, a driving unit to rotate the tubular element relative to the frame about a rotation axis, a plurality of catching elements extending outwardly through corresponding openings in the outer surface of the tubular element, and a reciprocating mechanism to move the plurality of catching elements during rotation of the tubular element between an outward position and an inward position in which free ends of the plurality of catching elements are at a larger distance from the outer surface of the tubular element in the outward position than in the inward position.

2. A cleaning device according to claim 1, wherein the free ends of the plurality of catching elements are flush with or recessed with respect to the outer surface of the tubular element in the inward position.

3. A cleaning device according to claim 1 or 2, wherein the outward position of the plurality of catching elements corresponds to a first angular position of the tubular element in which the plurality of catching elements are in a substantially horizontal orientation.

4. A cleaning device according to claim 3, wherein the inward position of the plurality of catching elements corresponds to a second angular position of the tubular element that has a substantially 180 degrees difference with the first angular position.

5. A cleaning device according to any of the claims 1-4, wherein the plurality of catching elements include a first set of catching elements distributed over the outer surface of the tubular element in a direction parallel to the rotation axis at a first side of the tubular element, and a second set of catching elements distributed over the outer surface of the tubular element in a direction parallel to the rotationaxis at a second side of the tubular element, and wherein preferably the second side is opposite the first side.

6. A cleaning device according claim 5, wherein the plurality of catching elements include a third set of catching elements distributed over the outer surface of the tubular element in a direction parallel to the rotation axis at a third side of the tubular element different from the first and second side.

7. A cleaning device according to claim 6, wherein the plurality of catching elements include a fourth set of catching elements distributed over the outer surface of the tubular element in a direction parallel to the rotation axis at a fourth side of the tubular element opposite the third side of the tubular element.

8. A cleaning device according to claim 5, wherein each catching element of the first set of catching elements is coupled to a respective catching element of the second set of catching elements.

9. A cleaning device according to claim 7, wherein each catching element of the third set of catching elements is coupled to a respective catching element of the fourth set of catching elements.

10. A wastewater system comprising: a tube element having an inlet for wastewater and an outlet for wastewater defining a flow direction from the inlet to the outlet, and a cleaning device according to claim 1 arranged at least partially in the tube element such that the plurality of catching elements move through the wastewater in a moving range in between the inward and outward position when moving towards the outward position.

11. A wastewater system according to claim 10, wherein the rotation axis of the tubular element of the cleaning device is substantially parallel to the flow direction defined by the tube element.

12. A wastewater system according to claim 10, wherein the rotation axis of the tubular element of the cleaning device is substantially perpendicular to the flow direction defined by the tube element.

13. A wastewater system according to any of claims 10-12, wherein the tube element has an open section, wherein the tubular element is arranged adjacent to an upper edge of the open section of the tube element, wherein the catchingelements extend away from the upper edge of the open section in the outward position and towards the upper edge of the open section in the inward position.

14. A wastewater system according to any of claims 10-13, further including a reception container arranged next to the tube element to receive articles removed from a wastewater flow in the tube element by the cleaning device.

15. A wastewater system according to any of claims 10-14, wherein when the catching elements move through the wastewater, a distance between free ends of the catching elements and the sewer element is at most 5% of a diameter of the tube element.

16. A method for cleaning wastewater flowing through a tube element, said method comprising the step of rotating a tubular element eccentrically through the wastewater along with a plurality of catching elements, which catching elements during rotation of the tubular element reciprocate between an outward position at one side of the tube element and an inward position at an opposite side of the tube element to remove articles from the wastewater using the catching elements.

17. A method according to claim 16, wherein in the inward position of the catching elements the free ends of the plurality of catching elements are flush with or recessed with respect to the outer surface of the tubular element, and wherein a scraper or knife is arranged close to or in engagement with the tubular element at the location where the catching elements are in the inward position to remove any debris or articles from the tubular element.

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