The present invention relates to a self-propelled vehicle configured for the removal of sediments, particularly for the removal of sediments in generally hazardous areas.

The invention is particularly suitable for cleaning and maintenance of storage tanks for industrial hazardous materials.

It is known the need of cyclically clean the storage tanks from sediments that settle and accumulate at the bottom of the tanks over time.

An example of such tanks are the storage tanks of oil or petrochemical plants.

Those tanks are often very large and may contain materials, such as hydrocarbon mixtures or polymer suspensions that, over time, can leave sediments on the bottom.

The presence of such sediments inside the tanks is undesirable, because it reduces the useful volume for storing material and because it can pollute the stored material itself.

The types of sediments that form at the bottom of those tanks vary widely, depending on the stored materials, on environmental conditions, and on the time elapsed between cleaning operations. Therefore, such sediments may be muddy or bituminous, sometimes containing large solid residues, such as crusts, and cannot be removed from the tank with the pumping equipment used in normal management of storage operations.

Furthermore, toxic or flammable compounds may be present inside the storage tanks, as well as in the sediment to be removed, making the entire work area potentially hazardous, and at risk of chemical, biological, or explosion contamination.

Sediment removal operations are particularly onerous because the human presence is strongly discouraged and equipment must meet strict safety requirements in accordance with the specific classification of the area, e.g., according to the international Atex classification.

To carry out such cleaning operations it is known to employ remotely controlled self-propelled vehicles capable of entering and moving inside the tanks. Those vehicles are equipped with sediment collection means and have a suction line, which is open at the bottom of the tank and extends to a pump located outside the tank, e.g. aboard a tanker truck, through which the sediments are drawn in and conveyed outside the tank, typically into the tanker truck itself. However, efficiency and capacity of these self- propelled vehicles are limited by the suction capacity of the pumps located outside the tank, which, in general, since they cannot be used inside explosion-prone areas, may be located at even very great distances from the tank in which the sediment removal operation is carried out.

Furthermore, the Applicant has noted that self-propelled vehicles intended for this type of operation must be as compact in size and volume as possible.

Indeed, access to tanks is generally allowed only through a side opening of a limited cross-section, typically a manhole with a circular cross-section of about 600 mm in diameter.

Furthermore, the compactness of the self-propelled vehicle facilitates the transport and storage steps for the self-propelled vehicle, as well as, of course, its movements inside the tanks.

To allow the self-propelled vehicle to be used in environments classified as hazardous, in particular in explosion-risk environments, it is also required that the onboard components be not electrically operated to avoid possible sparks.

It is the object of the present invention to provide a self-propelled vehicle structurally and functionally designed to overcome or reduce one or more of the drawbacks described above with reference to the prior art.

This object is achieved by the present invention by means of a self-propelled vehicle made according to the appended claims.

According to a first aspect of the invention, the self-propelled vehicle for the removal of sediments is preferably configured to operate in hazardous areas, e.g., classified Atex zone 1 or Atex zone 0.

Preferably, the self-propelled vehicle comprises a machine body and a moving device, which is constrained to the machine body and configured to move the self- propelled vehicle.

Preferably, the self-propelled vehicle comprises a remote-control system connected to the moving device to remotely control the displacement of the self- propelled vehicle.

According to a preferred aspect of the invention, the remote-control system comprises a hydraulic circuit comprising, for example, pressurized oil, connected to the moving device.

Preferably, the self-propelled vehicle comprises a pumping device mounted on the machine body.

Preferably, the pumping device is configured to draw in sediments through a suction line and pump them away from the self-propelled vehicle through a delivery line. Preferably, the pumping device comprises a lobe pump. By virtue of the aforesaid features, the self-propelled vehicle according to the present solution, having a lobe pump on board, can pump sediments outside the tank even at long distances without being limited by the suction capacity of the pump.

Also, the lobe pump is particularly compact compared with other positive displacement type pumps, so that the overall dimensions of the vehicle are kept within very small dimensions.

In some embodiments, the pumping device comprises a motor mounted on the machine body and associated with the lobe pump to control it in rotation.

More preferably, the motor is hydraulically actuated so that it can also be used in areas classified as hazardous.

Preferably, the motor is remotely controlled, and even more preferably it is controlled by the same control unit which controls the moving device of the self-propelled vehicle.

In some embodiments, the lobe pump comprises a pair of counter-rotating impellers, wherein each impeller is lobe-shaped. Preferably, each impeller is superficially coated with a layer of elastomeric material, such as NBR or SBR.

In this manner, the lobe pump can pump even semisolid material by virtue of the deformation ability of the lobes, which can adapt to the passage of solid residues. Preferably, the suction line of the lobe pump is fixed to the machine body.

Preferably, the suction line comprises a sediment mouth at the opposite end of the lobe pump.

Preferably, the inlet mouth is open on one front side of the self-propelled vehicle.

Preferably, a collection member is provided on one front side of the self-propelled vehicle, configured to convey the sediments to the inlet mouth of the suction line.

In a preferred embodiment, the lifting distance from the ground of the collection member is adjustable.

Preferably, the collection member is mounted on the machine body.

More preferably, the collection member is articulated on the machine body, and the self-propelled vehicle comprises an actuator extended between the machine body and the collection member so that the collection member can swing to and from the ground.

In this manner, the collection member can be raised off the ground by an appropriate amount such that it allows easier access to the inlet mouth of any solid residues in the sediments.

Preferably, the collection member comprises a pair of horizontal-axis augers mounted forward and laterally relative to the inlet mouth. The augers are preferably aligned and coaxial and are configured to convey the sediments toward the center of the front side of the self-propelled vehicle.

According to an embodiment, the machine body is mounted on said moving device with the at least limited ability of rotation about a horizontal axis.

Preferably, the machine body is articulated on the moving device and pivoted at the rear side of the moving device.

The self-propelled vehicle preferably comprises a lifting device extended between the machine body and the moving device appropriately configured to make at least the front of the machine body swing relative to the moving device.

In this manner, the front part of the machine body can be lifted by the moving device if necessary, facilitating the movement of the self-propelled vehicle on a variableinclination surface, such as climbing up a ramp or passing a step. In a preferred embodiment, the moving device comprises at least one rolling element intended to contact the ground and a hydraulically actuated motor to control the rolling element in rotation.

Preferably, the rolling element comprises a pair of tracks.

According to an embodiment, the self-propelled vehicle comprises an optical display apparatus, preferably mounted on the machine body.

In this manner, video images can be obtained directly from the self-propelled vehicle and can be sent to the control unit, allowing the operator to more effectively control the self-propelled vehicle even remotely, such as inside a tank.

According to an embodiment, the self-propelled vehicle comprises a washing device, preferably configured to deliver pressurized water to at least one front side of the vehicle.

Preferably, the pointing of the washing device is adjustable.

The features and advantages of the present invention will be more apparent in the following detailed description of a preferred embodiment, by way of non-limiting example, with reference to the accompanying drawings, wherein: figure 1 is a perspective view of a self-propelled vehicle according to the present invention; figure 2 is a perspective view of the vehicle of figure 1 , shown without the upper casing; figure 3 is a perspective view of the vehicle of figure 1 , sectioned along a longitudinal vertical plane; figure 4 is a side section view of the vehicle; and figure 5 is a top-plan view of the vehicle, sectioned along a longitudinal horizontal plane.

With reference to the above figures, the reference numeral 1 designates a self- propelled vehicle according to the present invention.

The self-propelled vehicle 1 is configured to remove sediments in hazardous areas, e.g., such as in Atex zone 0 or zone 1 classified areas, such as oil plant tanks.

The vehicle 1 comprises a machine body 2, in the form of a chassis, and a moving device 3, configured to move the self-propelled vehicle along a desired path.

Preferably, the vehicle is configured to advance along a predefined direction of advancement and has a front side A and an opposing rear side B.

Preferably, the machine body 2 is hinged to the moving device 3 at a pivot 4, with a horizontal axis, located on the rear side B of the self-propelled vehicle 1 .

The moving device 3 comprises a pair of tracks 5 controlled by a hydraulically actuated motor 6. A hydraulic actuator 7 extends between the movement device 3 and the machine body 2. The hydraulic actuator 7 acts as a lifting member and is configured to make the front part of the machine body 2 swing around the pin 4 with respect to the movement device 3, raising or lowering it. A pumping device 8, mounted on the machine body 2, comprises a suction line 9, a lobe pump 10, and a delivery line 11 .

The suction duct 9 is open on the front side A of the vehicle 1 at an inlet mouth 12. The inlet mouth 12 has an enlarged cross-section and is positioned at a reduced distance from the ground.

The lobe pump 10 comprises a pair of impellers 13 and 14, e.g., three-lobed shaped impellers, made of steel, and coated with an elastomeric layer, which is relatively deformable.

The impellers 13, 14 mesh with each other and are driven into rotation around respective axes parallel to each other, with an opposite direction of rotation to each other, by the action of a motor 15 and a gear transmission system 16.

The motor 15 is hydraulically actuated, and, for this purpose, is connected to a hydraulic circuit (not shown in the figure) at respective connections 17a, 17b, to allow the passage of pressurized fluid.

The delivery line 11 extends from the lobe pump 10 on the opposite side of the suction line 9 away from the self-propelled vehicle 1 , and can, for example, be connected to an external sediment collection tank.

To facilitate the removal of sediments by the pumping device 8, the self-propelled vehicle 1 also comprises a collection member 20 mounted on the front side A configured to convey sediment to the inlet mouth 12 of the suction line 9.

The collection member 20 comprises a pair of horizontal-axis augers 21 and 22 mounted forward and laterally relative to the inlet mouth 12.

The augers 21 , 22 are preferably aligned and coaxial and are configured to convey the sediments toward the center of the front side A of the self-propelled vehicle 1.

The collection member 20 is mounted on the machine body 2 with limited oscillation about a pivot 23, with a horizontal axis, due to the action of a hydraulic actuator 24 extending between the machine body 2 and the collection member 20, allowing the ground clearance of the collection member 20 to be adjusted.

An optical display apparatus 25, diagrammatically shown with a dashed line in figure 1 , is mounted on the body 2. Also a washing device (not shown in the figures), preferably with adjustable aiming, configured to deliver pressurized water at least to the front side A of the vehicle, is mounted on the body 2.

The self-propelled vehicle 1 further comprises a remote-control system (not shown) configured to control at least the action of the moving device 3, pumping device 8, actuators 7 and 24, collection member 20 and washing device.

The action of the various components of the self-propelled vehicle 1 is controlled by one or more hydraulic circuits connected to the self-propelled vehicle by means of respective attachments 19 located on the rear side B, all of which are connected to a control unit to which video images from the optical display apparatus 25 are also sent.

The self-propelled vehicle 1 is particularly suitable for removing sediment in hazardous areas, such as inside an oil plant tank, without requiring an operator to be present.

Indeed, the vehicle 1 can be easily moved along a desired path by means of the forwarding device 3, even on variable sloping terrain, e.g., by climbing up and down special ramps arranged to access the inside of a tank through an opening (manhole) with relatively small cross-section. If necessary, to facilitate such movements, the machine body 2 can be partially raised from the moving device 3 and similarly the collection member 20 may be more or less raised off the ground by the action of the actuator 24.

The optical display apparatus 25 allows the vehicle 1 to be moved accurately and effectively even in areas hidden from the operator's view, such as inside a tank.

Once placed in the area to be cleaned, the vehicle 1 starts the sediment removal operation by operating the collection member 20 and the pumping device 8.

In this manner, the sediments are conveyed by the augers 21 , 22 toward the inlet mouth 12 of the suction line, and, through the action of the lobe pump 10, the sediments are drawn in and moved away by the self-propelled vehicle 1 through the delivery line 11 , e.g., outside the tank toward a collection tank.

If necessary, the ground clearance of the collection member 20 can be appropriately adjusted by acting on the actuator 24.

The on board lobe pump 10 allows the self-propelled vehicle 1 to pump the collected sediments even at long distances from the vehicle.

Also, the small size lobe pump 10 on board has little significant influence on the overall volume of the self-propelled vehicle 1 , making the vehicle very compact, useful for accessing areas in which to operate, particularly inside tanks by passing through small openings, such as a 600-mm-diameter manhole, and useful when transporting and storing the vehicle itself.

The invention achieves the above-mentioned purposes, while offering numerous other benefits.

This application claims the priority of Italian Patent Application No. 202022000004311 , filed on October 21 , 2022 the subject matter of which is incorporated herein by reference.