WO2025186491A1 - Slag-cleaning robot and deslagging method - Google Patents

Abstract

Robot for cleaning slag from metal-melting furnaces, comprising a body of the robot attached to a head, an interchangeable arm to which there is attached a tool that contacts the slag, and wherein the interchangeable arm is attached to the head and preferably comprises two profiles that are fixedly attached to one another, preferably forming a right angle with one another. Also described is a cleaning system comprising said robot, as well as a slag-sweeping method, a cleaning method for cleaning the walls of the furnace, and a deslagging method, which are performed using the robot to ensure more efficient cleaning than when cleaning is performed manually and to avoid risks to operators.

Description

ROBOT FOR SLAG CLEANING AND DESLAGING METHOD

DESCRIPTION

OBJECT OF THE INVENTION

The present invention relates to a robot configured to perform slag cleaning (deslagging) operations in metal smelting furnaces. A cleaning system comprising said robot and methods for slag sweeping, cleaning furnace walls, and deslagging performed with said robot are also described.

TECHNICAL PROBLEM TO BE SOLVED AND BACKGROUND OF THE INVENTION

The metal smelting process generates a significant amount of slag. This waste or byproduct is generated during metallurgical smelting processes and consists mostly of homogeneous melts composed of free or bound oxides. This slag must be treated and managed using deslagging procedures.

Currently, deslagging procedures require continuous cleaning operations by operators. This, on the one hand, leads to numerous production stoppages to allow for cleaning operations; and, on the other hand, since the furnaces operate at very high temperatures (over 1,500°C, the melting point of the metal), the conditions are very harsh and dangerous for the workers responsible for cleaning.

During the smelting process, slag binds all impurities and unwanted compounds. It must be removed periodically to prevent it from adhering to the furnace walls, forming buildup and affecting the metallurgical efficiency of the operation and increasing the number and frequency of necessary maintenance operations.

Currently, there is no standardized, effective, and optimized solution for cleaning in induction metal melting furnaces. In today's induction furnaces, the molten metal is charged through the same upper gate, alloying agents are added, slag is removed, and the molten metal is transferred to the process ladle by tilting. Slag formation is a beneficial process during the melting operation, as it allows the metal mass to be separated from impurities, increasing the metallurgical efficiency of the process and producing a product with greater purity and added value.

Once the material has been melted and the alloys of interest have been added, coagulants are added so that the impurities rise to the surface and generate a solid conglomerate that can be removed after a specified time (before transferring the molten metal to the ladle). During the operation, some of the slag forms near the furnace walls, adhering to them in an undesirable manner. Therefore, an operator, holding a punching tool, removes the layer of slag that has formed from the surface of the melt after a few minutes.

However, this task requires very little precision given the extreme conditions under which it is performed. Therefore, during each deslagging cycle, some of the slag remains stuck to the walls of the induction furnace. Over time, the accumulated volume on the furnace walls and runner reaches unacceptable dimensions, and a maintenance shutdown is necessary to completely reheat the furnace. Depending on the workload, this can occur as frequently as every three weeks.

Therefore, given the characteristics of the process, it is necessary to carry out this cleaning operation (deslagging) continuously. Two types of cleaning are distinguished: one to remove the slag formed on the surface of the liquid metal, which is carried out manually using an interchangeable arm with a tool, and another to remove any slag residue that may have adhered to the inner wall of the furnace, which is carried out using hoists and heavy tools. Generally, the buildup generated on the furnace walls is so strongly adhered that the cleaning process ends up damaging the refractory itself.

Thus, the major technical problems of current deslagging procedures are the following:

• There are constant cycle stops as cleaning tasks need to be performed very continuously. Furthermore, at the end of each cycle, the walls should be cleaned to ensure maximum purity for the next batch, which requires cleaning every hour.

• Cleaning is associated with low job security since the process involves an operator working over an open pit.

• Cleaning involves poor operator ergonomics, especially due to the extreme working temperatures associated with the metal casting process.

• Since metal is a very hard material, slag removal requires highly demanding manual labor.

• Slag cleaning is an essential action that must be carried out optimally to avoid a reduction in furnace production capacity due to damage to the refractory lining. In other words, intensive slag cleaning is required, but it is currently performed with mechanical tools that cause wear on the hot-face lining and the resulting loss of heat from the furnace, thus reducing energy efficiency.

Therefore, the development of new techniques in the metal foundry sector is necessary to obtain an effective descaling solution that can resolve the problems associated with the complexity of cleaning tasks in industrial furnaces.

DESCRIPTION OF THE INVENTION

The invention relates to a slag cleaning robot in metal smelting furnaces comprising a robot body and comprising:

- a head with a proximal end, attached to the robot body, and a distal end, and inside which there is an automatic replacement mechanism;

- an arm, interchangeable, with a first end configured to be removably attached to the head, and with a second end, and where the first end is attached to the head through the automatic replacement mechanism;

- a tool attached to the second end of the arm in a removable and interchangeable manner and configured to come into contact with the slag.

The tool may be consumable.

The key to the invention is that it allows replacing an operator in the cleaning of ovens Metal casting. This allows for better cleaning results and avoids the risks associated with having cleaning operations performed by an operator.

Preferably, the head is rigidly attached to the robot body and contains a replacement mechanism configured to allow automatic replacement of the robot arm. At the proximal end of the head is a safety quick-release coupling that allows compatibility with any interchangeable arm. This allows for automatic replacement and automatic tightening without the need for an operator to supervise and tighten each change. The quick-release coupling may comprise two high-stress pneumatic grippers, which allow for arm replacement and withstand the stresses on the arm. Thus, the quick-release coupling system includes a locking and release mechanism that allows for efficient connection and disconnection of the tool arm.

The head also absorbs any potential overexertion caused by the robot's use in deslagging operations. To this end, the head incorporates a force compensation system or anti-collision system. This system uses sensors, controllers, and actuators to maintain the robot's balance and stability in the face of external forces. Real-time feedback from the sensors allows the robot's response to be adjusted, ensuring precise and safe performance in the cleaning and scraping tasks described above.

In preferred embodiments, the head comprises a heat-resistant coating such that the elements inside the head are protected from heat and dirt. Preferably, the head's connection comprises a direct inlet to the head, thus protecting it from heat. It may also comprise an anti-collision system configured to act as a fuse, preventing the robot from stopping during cleaning.

Thus, the robot may comprise force and torque sensors configured to measure external forces and moments applied to the end of the robot arm. These sensors provide real-time information on the forces and torques acting on the robot. In parallel, integrated PID controllers, using feedback from the force and torque sensors, implement a PID controller or other control algorithms to continuously adjust and correct the robot's positions and velocities. The controller minimizes discrepancies between the forces. desired and those measured by the sensors. Finally, the robot's actuators and motors are adjusted according to the control signals generated by the collision avoidance system. These adjustments allow the robot to react instantly to external forces and maintain its planned position and trajectory if the threshold value allows, or to modify the trajectory if the values collected by the force and torque sensors are above the threshold.

The head thus allows the elements that are most susceptible to the high temperatures reached in the oven to be cleaned (electrical, electronic and pneumatic elements) to be moved away and protected.

The interchangeable arm is a robot element configured to move the tool closer to the oven and perform the necessary cleaning movements. Thanks to the interchangeable arm, the robot's body and head can be kept away from the oven.

In one embodiment, it comprises at least one metal profile, and preferably at least two metal profiles, which are permanently connected to each other, preferably at a specific angle, which in one embodiment is a right angle. This geometry facilitates the storage of the arms when they are stored in a magazine accessible by the robot head for changing arms. Furthermore, this geometry allows the tool to be positioned in correspondence with the furnace without the head overcoming the furnace mouth. Preferably, the dimensions are such that they allow slag to be removed to a depth of between 50 and 3000 mm, measured from the furnace mouth. To this end, in one embodiment, the arm comprises a first segment, 1300 mm long, extending in the same longitudinal direction as the head, and a second segment, perpendicular to the first segment, 1100 mm long.

The tool is configured to come into direct contact with the molten metal in the furnace. The tool is interchangeable, allowing different configurations to be used depending on the cleaning stage. It can also be consumable, in which case it must be replaced after it has been partially or completely consumed.

In one embodiment, the tool comprises a metal plate, cut by Oxycut. This is an easy-to-change, low-cost tool.

In one possible embodiment, the tool is a trident-type tool. In this case, the tool has a trident-shaped configuration such that, upon contact with the molten metal and slag, the molten metal passes through the openings and the slag is carried away by the tool. Thus, using this tool, the slag can be moved to the area of interest (depending on the type of cleaning being performed or the cleaning stage).

In another possible embodiment, the tool is a shovel-type tool. In this case, the tool has no openings and is configured to exert greater force during movement. It may have a straight edge.

Trident-type and shovel-type tools are preferably used in steps related to locating slag in the center of the furnace. They can also be used in steps related to cleaning the furnace walls.

In another possible embodiment, the tool is a semicircular tool. In this embodiment, the tool is shaped like a half-moon/semicircle. This tool has a larger working surface area than trident- and shovel-type tools, so it is specifically configured for removing slag. This tool is preferably used in operations involving the removal of slag from the interior of the furnace and its transfer to an external container or other appropriate location. The half-moon configuration, with a non-angular perimeter, allows for more efficient slag removal tasks, as it is easier to collect the slag from the area in contact with the furnace walls. Angled tools allow some of the slag remaining between the tool and the wall (which is cylindrical) to drain away.

In an exemplary embodiment, with the semicircle type tool, the same amount of slag is removed in a single movement as, with trident or shovel type tools, two or three movements would be required (since these have a smaller working surface).

In another embodiment, the tool is a temperature probe. The temperature probe is used to obtain the temperature of the broth and may be consumable and/or be single-use.

Preferably, the robot also comprises a dosing receptacle which may be arranged on the interchangeable arm or on the head and which is described later.

Another object of the present invention is a slag cleaning system comprising a robot as previously described.

In one embodiment of the invention, the system also comprises an enclosure, arranged around the robot and at least one oven to be cleaned.

The station is preferably designed so that a single robot can perform the cleaning tasks for two furnaces. To do this, the robot is placed in a central position between the two furnaces. After completing the cleaning tasks, it deposits the slag in a defined and confined area at the top of the furnace, which is emptied during the furnace's turning. This follows the same configuration used to date in known state-of-the-art cleaning processes performed by operators. In implementations where the system includes an enclosure around the robot's work area, maximum levels of safety are achieved in the production plant, allowing for adequate coexistence with the rest of the plant's elements and the operators.

The robot position is determined by plant requirements, with limitations such as proximity to the furnaces and/or limited space between furnaces.

The force applied by the robot must be sufficient to allow for thorough cleaning of the furnace interior. Since the interior wall of the furnace crucible is lined with refractory material, which maintains the necessary high temperatures and achieves maximum process efficiency, the force exerted by the robot cannot be so strong as to damage this material. The robot is designed to remove slag without damaging the refractory material itself. Furthermore, the trajectories of the robot arm with the various tools are designed with precise movements and to avoid collisions.

In a preferred embodiment, the robot is designed for a nominal payload of 120 kg (1177 N) in order to optimize the dynamic performance of the robot. The payload maximum is preferably 167 kg (1638 N) which only applies if the position of the center of mass is 0 mm.

The robot operates according to theoretical force curves. Force and moment sensors constantly measure the position of the head relative to the central axis of the robot body, and maximum force thresholds are automatically established based on the robot's theoretical working force curves.

The relationship between the distance at which the force is exerted, measured relative to the robot's body axis, and the exercisable force is approximately linear. The minimum exercisable force corresponds to the maximum distance between the point where the force is exerted and the robot's axis (589 N), and increases as the distance decreases.

In one possible embodiment, the system comprises a ventilated cover for the robot. This cover is preferably a protective cover comprising a heat-resistant coating, is internally insulated, and has forced ventilation from the outside. The cover is custom-made to comply with the maximum width limitation of 1000 mm between ovens.

The system may also include at least one basket for emptying the slag extracted from the furnaces. This basket is preferably maneuverable with an overhead crane and forklift and has swing doors at the bottom for emptying.

Likewise, the system may comprise a tool cleaning station, comprising at least one mechanical stop in the form of a scraper, configured to come into contact with the robot tool such that it allows cleaning the slag residue from the tools, extending their useful life and thus avoiding the reintroduction of slag residue into the furnace.

In an embodiment of the invention, the tool cleaning station comprises a scraper support on which the at least one mechanical stop is located and which has an “L” shaped configuration such that it allows the slag to slide from the lower part of the mechanical stop. Likewise, the tool cleaning station comprises a slag tray, of a length sufficient to ensure that all the slag falling from the scrapers falls into said tray. In addition, the The tray includes side plates that prevent the slag from falling into the gap between the fixed and moving parts of the platform. These side plates prevent the removed slag from spreading over the top of the furnace. This (by confining the area where the removed slag is deposited) optimizes the cleaning process of the scraper tools and improves the slag's fall into the container during the turning process.

The trajectories of the robot arm with the tool are defined so that the majority of the slag falls on the part of the slag tray closest to the slag dumping basket. Furthermore, the slag is preferably transported from the furnace to the scraper horizontally, so that the slag does not need to stick to the tool.

The system may also comprise a coagulant (Freslag) dispenser in a dosing station, with at least one feed position accessible from outside the enclosure to allow the dispenser to be refilled by an operator. The system may also include a control system for the quantity of Freslag to be fed, with automatic dosing and low coagulant level control. The robot may also comprise a dosing receptacle for receiving a predetermined quantity of coagulant. Preferably, the dosing receptacle is located on the interchangeable arm or on the headstock, such that, when the headstock is moved with the arm to the dosing station, the receptacle is filled with the required quantity of coagulant through a programmed dosage, and when it is moved to the furnace, it can be poured onto the molten metal. This receptacle thus allows the coagulant to be transported from the dispenser in the dosing station to the furnace(s). Preferably, while pouring is taking place, the arm continues to move, even more preferably in a circular path, to facilitate a more efficient reaction, and therefore the production of slag.

Furthermore, the system preferably includes an electrical cabinet and HMI (human-machine interface) configured to allow interaction between the operator and the robot. Both elements are preferably located away from the ovens, and the electrical cabinet preferably has forced ventilation and dust protection.

An arm and tool warehouse can also be part of the system, located in front of the robot body so that the robot can move its head to the magazine to change the arm and/or the tool arm during cleaning processes. The magazine is preferably accessible from inside the enclosure by the robot head and is accessible from outside the enclosure to allow tool changes.

Preferably the system also comprises a measuring station for TCP calibration.

In general terms, the TCP (Tool Center Point) is the specific point a robot uses as a reference for motion and control operations. TCP calibration is the process of adjusting and verifying the exact position and orientation of the TCP relative to the robot's coordinate system.

A calibration station includes high-precision measuring devices to accurately determine the position and orientation of the TCP in three-dimensional space. During calibration, parameters are adjusted and measurements are taken to ensure the robot can perform movements and operations with the precision required for its tasks.

TCP calibration is crucial to ensuring accurate robot operations, especially in applications where precise positioning and orientation are required.

The described system, with two ovens and a robot positioned between them, allows the operator to access the area of one of the ovens to load material while the robot works in the area of the other oven, and vice versa. Furthermore, in one embodiment, the enclosure comprises two doors, each positioned in correspondence with one of the ovens. While the doors are closed, the robot can access both ovens, and when one of them is opened, the robot works alone in the other oven, thus preventing any operator from being injured by the robot while working in the corresponding oven. Also to prevent accidents, the arm/tool changing station preferably includes a presence sensor such that, when the presence of an operator is detected at the station, the robot cannot access said station. In this way, the safety of operators is guaranteed at all times, while achieving a much more efficient operating system than the current one.

The ovens are preferably arranged close together to optimize the installation space. Therefore, when one of the ovens is being turned, the robot remains in a resting position, preferably facing the storage area.

Additionally, and preferably, the robot can have the autonomy to automatically change the thermocouple after each temperature measurement cycle.

The arm and tool magazine may also include a set of thermocouples (spare parts available for use at any time) such that the robot can automatically move the head with the tool to said set of thermocouples and install a new thermocouple. This set of thermocouples has low-level detection and is arranged so that an operator can refill it by accessing the magazine without endangering themselves. Furthermore, the magazine may also contain a tool configured to remove the burned-out thermocouple, dropping it into the magazine's slag bin.

Additionally, and preferably, the robot has the ability to perform sample extraction automatically. A scoop-shaped tool has been designed for this step. The robot extracts the sample with the scoop-shaped tool and inverts it into a mold, which can be made of graphite, placed in the same position in each of the furnaces.

The operator places the mold manually each time a sample is obtained. The mold must always be placed in a specific, delimited area (marked, for example, by painting the floor). The process is the same as that performed by the operator, but specific programming has been implemented so that the robot can perform it.

Additionally, and preferably, the material to be added can be weighed and dosed automatically, either in the furnace or in the ladle. For this purpose, the robot may also include a tray-type tool. A Weighing station equipped with a centering system that allows the tool to be placed on it and the weight of the material to be added monitored. This operation is similar to pouring coagulant, but in this case, the solid to be added has a different density, and a larger volume is added.

To extend the tool's useful life, in a preferred embodiment of the invention, the tool is painted with a refractory coating, which allows the slag that sticks to the tool to be removed more efficiently. This is because the slag sticks to the coating and, after the furnace cleaning and tool cooling process, flakes off, allowing for easier removal by a mechanical percussion process. In this way, the coating falls off along with the slag that adhered to it.

Thus, the system preferably also includes a tool coating station and a tool coating removal station, with a hammer drill. These stations perform tool painting operations, and after use, the tools are struck to remove the flaked coating and adhering slag. These operations are preferably performed automatically.

In one possible embodiment, the coating station is arranged, in the system, on one side of the arm and tool magazine. The coating station may comprise a receptacle with at least one opening, and inside said receptacle comprises a plurality of adjustable nozzles through which the steps of painting the tools are performed. In embodiments of the cleaning method in which, before using the tools for cleaning, they are coated (to obtain the previously described advantages).

Likewise, the system may comprise at least one coating removal station, as previously described. Preferably, the system comprises two coating removal stations, one corresponding to each of the furnaces to be cleaned. Preferably, these stations comprise a hammer drill such that specific movements are programmed for the robot's trajectories so that the tool comes into contact with the hammer drill, which is responsible for removing the coating and, therefore, the slag adhering to it. Preferably, the coating removal stations are arranged on the slag removal trays. associated with each furnace such that, with each turn, the slag will fall into the corresponding basket.

Thus, the robot and cleaning system of the invention are auxiliary elements for the smelting furnace and are designed to carry out cleaning operations based on robotic technologies, allowing for maximum safety and repeatability of the cleaning operation. This results in increased productivity and cost reduction, greater production flexibility, reduced waste and shrinkage, and increased efficiency.

The invention also relates to a slag sweeping method, a furnace wall cleaning method and a deslagging method.

The methods described can be performed automatically, considering specific time intervals between cycles, or semi-automatically, so that an operator determines which method to perform at any given time.

The slag sweeping method of the present invention is carried out with the robot previously described and comprises at least the following steps:

- dose a certain amount of coagulant into the oven;

- radially sweeping, with the tool, from the walls of the furnace towards the center of the furnace by angularly equidistant movements between them the upper surface of the molten metal, where the slag is located, until covering the entire area of the furnace opening such that all the slag is concentrated in the center of the furnace;

- remove the slag by means of an upward movement of the tool, with the tool in a horizontal position.

Thus, the first step is to dose the coagulant into the furnace. The dosing receptacle is preferably used for this operation. The coagulant can be loaded into the tool, as previously described, at the dosing station using a coagulant dispenser (which can be automatic).

The next stage, radial sweeping, is preferably performed with a trident-type tool. This stage aims to concentrate the slag in the center of the furnace, not clean the walls, so the sweep starts at a distance from the walls sufficient to avoid deformations due to possible collisions of the tool.

In a preferred embodiment of the invention, before performing the radial sweeping step, a tool calibration step is performed to accurately determine the measurements of the specific tool to be used and thus adapt the trajectory to said specific measurements.

Once the slag is concentrated in the center of the furnace, a tool change is made so that the next step, slag removal, is performed with the crescent-shaped tool. As previously described, the slag is collected by an upward movement of the arm with the tool in a horizontal position. Due to the cylindrical geometry of the furnace, the maximum angles of attack of the robot arm with the corresponding tool vary depending on the depth of the molten metal in the furnace.

A method of cleaning the walls of an oven with the robot described is also described, which comprises the steps of:

- determine the filling level of the oven;

- define a tool movement path, based on possible overgrowths on the furnace walls and the furnace filling level determined in the previous stage, to sweep the perimeter of the furnace mouth;

- remove the slag dragged by the tool with an upward movement, with the tool in a horizontal position.

The stage of determining the oven fill level involves taking the temperature using the thermocouple (temperature-taking tool) and determining, using the temperature and the position of the robot (the movement made by the arm until the tool came into contact with the broth, which is determined by a sudden increase in temperature measured by the thermocouple), the oven fill height. To do this, the temperature-taking tool must be inserted into the oven until the tip of the temperature-taking tool melts. At that moment, the temperature is measured in real time and the movement made by the arm with the tool from a "zero level" of the oven until the moment in which a sudden rise in temperature is detected (when the temperature-taking tool temperature is introduced into the broth). This position is memorized as the filling height of the oven.

Preferably, the robot uses a trident-type tool to clean the furnace walls. Also preferably, the cleaning path includes the tool entering through the center of the furnace and sweeping along the perimeter of the furnace. Before performing the wall-cleaning path, in one embodiment of the invention, the tool is measured. This allows the path to be defined more precisely.

Once the slag has approached the furnace walls (by moving the trident-type tool along the predefined path), a tool change is preferably performed, and the slag removal step is carried out using a crescent-type tool. The removed slag is preferably deposited in a container within the system.

As previously described, due to the cylindrical geometry of the furnace, the maximum angles of attack of the robot vary depending on the depth at which the melt (molten metal) is located.

The optimal temperature for cleaning operations is the same as the optimal temperature for the melting process, which ranges from 1550 to 1700°C depending on the alloy being manufactured. In any case, the robot can operate at temperatures ranging from 0°C to 2000°C. Above a certain temperature, the robot preferably operates with special thermal protection (such as a sheath, heat-resistant coating, etc.).

Preferably, before each use of each tool, said tool is painted to facilitate subsequent removal of the slag.

Another object of the present invention is a deslagging method comprising first performing a slag sweeping method and subsequently a furnace wall cleaning method as previously described.

Thus, the robot, the system and the cleaning and deslagging methods described allow accurately reproduce the movements currently performed by the operator, and also allow for movements that the operator is currently unable to perform for ergonomic reasons, which are extremely beneficial for proper furnace maintenance. All this is achieved by precisely removing the material to be removed (slag) and any growth generated on the furnace walls, while keeping the refractory intact, in order to maximize the furnace's energy efficiency and preserve its original design and volume.

Furthermore, it is possible to control the operation and detect problems or incidents in the cleaning process. This allows future operational planning tasks for the equipment to be carried out based on precise measurements of parameters that are critical to determining whether the cleaning has been carried out effectively. The system is also capable of automatically measuring the bath temperature during the cleaning cycle, as well as the height of the metal mixture. This value is currently simply estimated by the operator, but thanks to the invention, this measurement can be performed quantitatively and accurately, allowing the data to be used in subsequent processing.

The developed work method increases the reliability of cleaning cycles and allows for repeatability and traceability. This allows for better monitoring of results, providing real-time information to resolve potential incidents or errors.

BRIEF DESCRIPTION OF THE FIGURES

To complete the description and in order to help better understand the characteristics of the invention, a set of drawings is attached to this specification, as an integral part thereof, in which the following has been represented for illustrative and non-limiting purposes:

Figure 1 represents a perspective view of the robot of the invention.

Figure 2 represents a perspective view of the cleaning system.

Figure 3A represents a perspective view of the arm and tool magazine. Figure 3B represents a side view of the arm and tool magazine.

Figure 4 represents a top plan view of the cleaning system.

Below is a list of the numerical references associated with the different elements of the invention:

1: body; 2: head; 2.1: proximal end; 2.2: distal end; 3: arm; 3.1: first end; 3.2: second end; 4: tool; 5: furnace; 6: first segment; 7: second segment; 8: enclosure; 9: tool cleaning station; 10: mechanical stop; 11: scraper support; 12: coagulant dispenser; 13: dosing receptacle; 14: arm and tool magazine; 15: basket; 16: material loading tool; 17: coating station; 18: thermocouple assembly

DETAILED DESCRIPTION

The present invention should not be limited to the embodiment described herein. Other configurations may be realized by those skilled in the art in light of this description. Accordingly, the scope of the invention is defined by the following claims.

A perspective view of the robot of the invention is shown in Figure 1. The robot for cleaning slag from a metal smelting furnace (5) of the invention comprises, as can be seen in Figure 1: a robot body (1); a head (2) with a proximal end (2.1), attached to the robot body (1), and a distal end (2.2), and inside the head there is a replacement mechanism); an arm (3) with a first end (3.1), attached to the head (2) in a removable and interchangeable manner, and with a second end (3.2), and the arm (3) has a geometry such that it allows a tool (4) to be positioned in the furnace (5) and to keep the head (2) in an offset position with respect to the furnace (5), and where the head replacement mechanism comprises a quick release coupling system with a locking and release mechanism configured to allow the connection and disconnection of the interchangeable arms (3) to the head (2); - the tool (4), attached to the second end (3.2) of the arm (3) in a removable and interchangeable manner, and which is configured to come into contact with the slag.

Preferably, the tool is selected from:

- a trident-type tool (4) having a trident-shaped configuration such that, upon contact with the molten metal and the slag, the molten metal passes through the openings and the slag is carried away by the tool;

-a shovel-type tool (4), without openings, configured to exert greater force during its movement and has a straight leading edge;

-a semicircle type tool (4) with a larger working surface area than the trident and spade type tools and with a semicircular perimeter, and which is preferably configured to remove slag; or

-a thermocouple type tool (4), configured to measure the temperature of the molten metal.

The tool (4) may be consumable so that, when it comes into contact with the slag and/or molten metal, it is consumed and must be replaced with a new one every certain period of time.

The head (2) may comprise an anti-heat coating to ensure the protection of the mechanical and electronic elements found inside, such as the replacement mechanism that allows the arms (3) to be changed automatically.

In a possible embodiment, as seen in said figure 1, the arm comprises a first segment (6), attached to the head (2), and a second segment (7), attached to the tool (4), and where the first segment (6) and the second segment (7) are fixedly attached to each other, preferably at a right angle.

In one possible embodiment, the tool (4) is coated with a conventional refractory coating. As previously described, this embodiment facilitates subsequent removal of the slag.

Preferably, the robot also comprises a dosing receptacle (13) which is a hollow body with at least one opening which is preferably arranged in the interchangeable arm (3) or in the head (2) (as is the case in the example of Figure 1). moving the head (2) and/or the arm (3) to a dosing station in which a coagulant doser (12) is located, the coagulant is dosed in said dosing receptacle (13) and, by moving the head (2) and/or the arm (3) to the furnace (5), the coagulant is poured onto the molten metal. To carry out said pouring, preferably, a circular path is followed with the head (2) and/or the arm (3) during the pouring (dosing) that improves the efficiency of the mixture.

A slag cleaning system is also described, comprising a robot as previously described and at least one furnace (5) to be cleaned. Preferably, the system also comprises at least one enclosure (8) around said furnace (5) and robot. By means of the enclosure (8), the area of action of the robot is limited and the passage of people is prevented, which is especially important when the robot is operating, in order to avoid possible accidents/collisions.

Figure 2 shows a cleaning system with two ovens (5) to be cleaned and a robot arranged between them. In this way, even when the robot body (1) is arranged in a fixed position, it can provide cleaning service to both ovens (5).

In one embodiment of the invention, the system comprises a tool cleaning station (9) with at least one mechanical stop (10) in the form of a scraper configured to come into contact with the tool (4) of the robot. Preferably, the tool cleaning station also comprises a scraping support (11), in which the mechanical stop (10) is located, and which has an “L” shaped configuration that allows the slag to slide through it from the mechanical stop. The cleaning station may also comprise a slag collection tray, arranged downstream of the scraping support (11).

Furthermore, the system may comprise a coagulant dispenser (12) configured to dispense a specific quantity of coagulant into a dosing receptacle (13) arranged in the head (2) or in the arm (3) of the robot.

The system may also comprise at least one basket (15) for pouring the slag extracted from the furnaces (5). Preferably, this basket (15) can be handled with an overhead crane and forklift and has swing doors at the bottom for emptying. The system comprises an arm and tool magazine (14), arranged in front of the robot body (1) and in said magazine (14) there are a plurality of arms (3) and/or tools (4). A perspective view and a side view of said magazine (14) are shown in Figures 3A-B.

In figures 3A-B you can also see a set of thermocouples (18), a coagulant dispenser (12), a material loading tool (16) and a tool coating station (17).

Also preferably, the system may comprise a tool coating station (17) comprising at least one receptacle inside which comprises a plurality of nozzles configured to paint the robot tool, and a coating removal station comprising at least one hammer drill configured to move along a determined trajectory so that the hammer drill and the tool come into contact.

Figure 4 shows a view of the system from the top floor. In this case, the system comprises two ovens (5) to be cleaned, with the robot arranged between them and the enclosure (8) encompassing all these elements.

Depending on the position of the robot body (1), the position of the ovens (5) and the filling level of said ovens (5), the angle at which the tool (4) is introduced into the oven (5) varies. Thus, in order to carry out the different types of cleaning described below, it is necessary to determine the filling level and subsequently adapt the movement of the arm (3), and therefore of the tool (4), to said filling level. The position of the robot body (1) and the positions of the ovens (5) are fixed, so the determining parameter for adapting the trajectories to be carried out by the robot arm (3) is the filling height (filling level).

The invention also provides a slag sweeping method, a furnace wall cleaning method, and a deslagging method comprising both. All the methods of the invention are performed using the robot described.

The method of sweeping slag with the robot of the invention comprises the steps of: - dosing a determined quantity of coagulant in the furnace (5); - radially sweeping, with the tool (4), from the walls of the furnace (5) towards the center of the furnace (5) by means of angularly equidistant movements between them, the upper surface of the molten metal, where the slag is located, until covering the entire area of the opening of the furnace (5) such that all the slag is concentrated in the center of the furnace (5);

- remove the slag by means of an upward movement of the tool (4), with the tool (4) in a horizontal position.

Preferably, before the step of dosing a determined quantity of coagulant into the oven (5), a step of taking the temperature of the molten metal is carried out by using a thermocouple type tool (4).

In a specific embodiment of the invention, the method comprises the following steps: moving the head (2) and the arm (3) of the robot towards the arm and tool magazine (14); selecting a temperature measuring tool (4) (thermocouple type tool) such that an automatic temperature measuring tool dispenser arranged in the arm and tool magazine (14) inserts the selected tool (4) into the arm (3); moving the arm (3) with the tool (4) to the mouth of the furnace (5) (to the central position obtained according to the last calibration that has been carried out) and moving the arm (3) with the tool (4) downwards, to the zero level of the mouth of the furnace (5); moving the arm (3) with the tool (4) from the zero level of the mouth of the furnace (5) to the surface of the molten metal and measuring and recording the temperature with the thermocouple type tool (4) (temperature measuring tool (4); move the arm (3) with the tool (4) back to the arm and tool magazine (14) and perform a tool (4) change by selecting a shovel type tool (4); move the arm (3) to the automatic coagulant dispenser (12) until a determined quantity of coagulant is poured into a dosing receptacle (13) of the robot; move the arm (3) back to the central position of the mouth of the furnace (5), and make circular movements with the head (2) and the arm (3) over the entire surface of the mouth of the furnace, dosing a determined quantity of coagulant onto the molten metal in the furnace (5); radially sweeping, with the tool (4), from the walls of the furnace (5) towards the center of the furnace (5), by means of angularly equidistant movements, the upper surface of the molten metal, where the slag is located, until the entire area of the opening of the furnace (5) is covered such that all the slag is concentrated in the center of the furnace (5); moving the arm (3) with the tool (4) to the arm and tool magazine (14) and changing the shovel-type tool (4) for a crescent-type tool (4); moving the arm (3) with the tool (4) back to the center of the furnace (5) and removing the slag by means of an upward movement of the tool (4), with the tool (4) in a horizontal position; moving the arm (3) with the tool (4) to the slag cleaning station (9), performing preprogrammed movements to remove the slag adhering to the tool (4); Move the arm (3) with the tool (4) to the arm and tool magazine (14).

Preferably, the step of removing slag adhering to the tool comprises a step of bringing the surface of the tool (4) closer to the mechanical stop (10), preferably with an angle of inclination between the tool (4) and the mechanical stop (10) of between 15° and 45°, thus performing cleaning by mechanical contact.

In the step of moving the arm (3) with the tool (4) to the mouth of the oven (5), to the central position of the oven (5) obtained according to the last calibration that has been carried out, said calibration determines the filling level of the oven and, based on this, the angle at which the tool (4) is introduced into the oven (5) (depending on the relative position of the oven (5) and the body (1) of the robot). It is also calibrated with the TCP that the robot continues to position the arm (3) in the center of the oven (5) each time it performs a cleaning cycle.

Temperature recording is preferably done automatically by the robot itself.

The method of cleaning the walls of an oven with the robot described includes the following: stages of:

- determine the filling level of the oven (5);

- define a movement path of the tool (4) based on possible growths in the walls of the furnace (5) and the filling level of the furnace (5) determined in the previous stage, to sweep the perimeter of the mouth of the furnace (5);

- remove the slag dragged by the tool (4) with an upward movement, with the tool (4) in a horizontal position.

Preferably, prior to the step of determining the filling level of the furnace (5), a step of taking the temperature of the molten metal is carried out by using the thermocouple type tool (4).

In a specific embodiment of the invention, the method for scanning the walls of the furnace (5) comprises the following steps: moving the head (2) and the arm (3) of the robot towards the arm and tool magazine (14); selecting a temperature measuring tool (4) such that an automatic temperature measuring tool dispenser arranged in the arm and tool magazine (14) inserts the selected tool (4) into the arm (3); moving the arm (3) with the tool (4) to the mouth of the furnace (5), to the central position obtained according to the last calibration that has been carried out and moving the arm (3) with the tool (4) downwards to the zero level of the mouth of the furnace (5); moving the arm (3) with the tool (4) from the zero level of the mouth of the furnace (5) to the surface of the molten metal and measuring and recording the temperature with the temperature measuring tool (4); move the arm (3) with the tool (4) back to the arm and tool magazine (14) and carry out a tool (4) change by selecting a crescent-shaped tool (4); define a movement path for the tool (4), depending on possible growths in the walls of the furnace (5) and the filling level of the furnace (5) determined in the previous stage, to sweep the perimeter of the mouth of the furnace (5); extract the slag dragged by the tool (4) with an upward movement, with the tool (4) in a horizontal position; move the arm (3) with the tool (4) with the slag to the tool cleaning station (9) and carry out, at said station, a plurality of movements of approximation of the surface of the tool to the scraping support (11) with an angle of inclination comprised between 5 ^° and 85° such that the tool is cleaned by mechanical contact with the mechanical stop (10) of the scraping support (11); move the arm (3) with the tool (4) to the arm and tool magazine (14).

As in the method previously described, in the step of moving the arm (3) with the tool (4) to the mouth of the oven (5), to the central position obtained according to the last calibration that has been carried out, said calibration determines the filling level of the oven (5) and, based on this, the angle at which the tool is introduced into the oven (5) (depending on the relative position of the oven (5) and the body (1) of the robot). It is also calibrated with the TCP that the robot continues to position the arm (3) in the center of the oven (5) each time it performs a cleaning cycle.

Also in this method, preferably, the recording of the measured temperature is done automatically by the robot.

Finally, the invention describes a method of deslagging a furnace (5) that comprises performing a slag sweeping method and then performing a method of cleaning the walls of the furnace (5) as previously described.

Claims

1.- Robot for cleaning slag from a metal smelting furnace (5) characterized in that it comprises: a robot body (1); a head (2) with a proximal end (2.1), attached to the robot body (1), and a distal end (2.2), and inside the head there is a replacement mechanism); an arm (3) with a first end (3.1), attached to the head (2) in a removable and interchangeable manner, and with a second end (3.2), and the arm (3) has a geometry such that it allows a tool (4) to be positioned in the furnace (5) and to keep the head (2) in an offset position with respect to the furnace (5), and where the head replacement mechanism comprises a quick release coupling system with a locking and release mechanism configured to allow the connection and disconnection of the interchangeable arms (3) to the head (2); - the tool (4), attached to the second end (3.2) of the arm (3) in a removable and interchangeable manner, and which is configured to come into contact with the slag. 2.- Robot according to claim 1, wherein the tool (4) is selected from: - a trident-type tool (4) having a trident-shaped configuration such that, upon contact with the molten metal and the slag, the molten metal passes through the openings, and the slag is carried away by the tool; - a shovel-type tool (4), without openings, configured to exert greater force during its movement; - a semicircle type tool (4) with a larger working surface area than the trident type and shovel type tools; or - a thermocouple tool (4). 3.- Robot according to any one of the preceding claims in which the tool (4) is consumable. 4.- Robot according to any one of the preceding claims, wherein the head (2) comprises an anti-heat coating. 5.- Robot according to any one of the preceding claims, wherein the arm comprises a first segment (6), connected to the head (2), and a second segment (7), connected to the tool, and where the first segment and the second segment are fixedly connected to each other. 6.- Robot according to any one of claims 1 to 5, wherein the tool is painted with conventional coating. 7.- Robot according to any one of claims 1 to 6, wherein the head or arm of the robot comprises a dosing receptacle configured to receive a determined quantity of coagulant. 8.- Slag cleaning system characterized in that it comprises a robot as described in any one of claims 1 to 7 and at least one furnace (5) to be cleaned. 9.- System according to claim 8, additionally comprising an enclosure (8), arranged around the robot and the at least one oven (5) to be cleaned. 10.- System according to any one of claims 8 to 9 comprising a tool cleaning station (9) with at least one mechanical stop (10) in the form of a scraper configured to come into contact with the tool (4) of the robot. 11.- System according to claim 10, wherein the tool cleaning station also comprises a scraping support (11), in which the mechanical stop (10) is located, and which has an “L” shaped configuration that allows the slag to slide through it from the mechanical stop (10). 12.- System according to claim 11, wherein the cleaning station comprises a slag collection tray, arranged after the scraping support (11). 13.- System according to any one of claims 8 to 12 comprising a coagulant dispenser (12) configured to pour a specific quantity of coagulant into a dosing receptacle (13) arranged in the arm (3) or in the head (2) of the robot. 14.- System according to any one of claims 8 to 13 comprising an arm and tool magazine (14), arranged in front of the body (1) of the robot and in said magazine there are a plurality of arms (3) and/or tools (4). 15.- System according to any one of claims 8 to 14 comprising a tool coating station comprising at least one receptacle inside which comprises a plurality of nozzles configured to paint the robot tool, and a coating removal station comprising at least one hammer drill configured to move along a determined trajectory so that the hammer drill and the tool come into contact. 16.- Method of sweeping slag with the robot of any one of claims 1 to 7 comprising the steps of: - dose a given quantity of coagulant into the oven (5); - radially sweeping, with the tool (4), from the walls of the furnace (5) towards the center of the furnace (5), by means of movements angularly equidistant from each other, the upper surface of the molten metal, where the slag is located, until covering the entire area of the opening of the furnace (5) such that all the slag is concentrated in the center of the furnace (5); - remove the slag by means of an upward movement of the tool (4), with the tool (4) in a horizontal position. 17.- Slag sweeping method according to claim 16, in which prior to the step of dosing a determined quantity of coagulant, a step of taking the temperature of the molten metal is carried out. 18.- Method of cleaning the walls of an oven with the robot according to any one of claims 1 to 7 comprising the steps of: - determine the filling level of the oven (5); - define a movement path of the tool (4), depending on possible growths in the walls of the furnace (5) and the filling level of the furnace (5) determined in the previous stage, to sweep the perimeter of the mouth of the furnace; - remove the slag dragged by the tool (4) with an upward movement, with the tool (4) in a horizontal position. 19.- Method for cleaning the walls of an oven according to claim 18, wherein Prior to the step of determining the filling level of the furnace (5), a step of taking the temperature of the molten metal is carried out. 20. A method for deslagging a furnace comprising performing: a) a slag sweeping method according to any one of claims 16 to 17; and subsequently b) a method for cleaning the furnace walls according to any one of claims 18 to 19.