EP0795360A1 - Method and device for cleaning ducts - Google Patents

Abstract

The procedure for maintaining the walls of a channel includes projecting a peal-able film on to the walls. After a certain period of use this film is then mechanically removed together with the accumulation of grease, dirt and dust and these particles are blown of the conduit. Both the application of this film, and the subsequent removal are carried out by a remotely controlled robot (1) with a microprocessor programmed to control different elements of the robot. The microprocessor is connected to an external station for control of the robot and inspection of the channel. The robot carries lights, and a video camera system for transmission of video images from the robot back to the remote monitoring station. The rotor comprises a central body with driving wheels mounted on pivoting arms to run against the internal surfaces of the conduit.

Description

The present invention relates to a method and a device for cleaning ventilation ducts or ducts intended in particular, but not exclusively, for industrial kitchens.

In these buildings, large section pipes evacuate to the outside the various vapors and aerosols generated by the kitchens. Despite careful filtering, grease is gradually deposited on the walls of the duct. These combustible deposits constitute a certain danger in the event of a fire on a cooking point at the entrance to the pipeline. In addition, for hygienic reasons, the ducts or ducts must be cleaned regularly.

Currently, the conduits are degreased manually using a pressurized water cleaner. This process has several drawbacks: use of water in large quantities, dirty water having to be recovered under difficult conditions. Access to the interior of the conduits is never easy and often impossible because of the long lengths, elbows and variations in section. Finally it is impossible to completely remove certain deposits.

Cleaning devices have already been proposed.

FR-B-1 571 793 discloses a device with the aid of which the inner wall of a tube can be cleaned and / or provided with a protective coating comprising a motor for driving the working members rotate in opposite directions opposite rotation, a spring applying the guide rollers against the inner wall of the tube. The device is pulled by a pull cable inside the tube. However, such a device can only circulate in a linear tube or pipe or with a large radius of curvature. GB-B-719 254 describes a carriage for cleaning the interior of pipelines on which a motor drives a brush. US-A-3037228 describes a machine for deburring internal welds in pipes. FR-A-1 697 088 describes an apparatus for treating the internal walls of water supply conduits, comprising a carriage provided with two groups of three rollers distributed at 120 ° from one another, controlled by trains of 'gear. DE-A-2 339 868 describes another cleaning device.

All the documents of the prior art only work properly if the pipes are of circular section and do not have bends with radius of curvature or too small an angle.

The object of the present invention is to overcome the drawbacks of known systems and to ensure correct operation whatever the configuration of the pipes.

According to the present invention, the method of cleaning the duct walls is characterized in that it consists in spraying the walls with a peelable film of acrylic type.

After a certain time, when the deposit of grease and dirt is considered sufficient, the film is removed by mechanical peeling and suction with the grease and a new layer is sprayed. Thus, the interior of the pipe is coated with a temporary coating which is destroyed on each cleaning but in the meantime ensures the sealing thereof and the reception of grease and dirt.

The present invention also relates to a self-propelled device with distributed motivity constituting a remote-controlled robot and capable of carrying different tools and in particular an inspection camera, a film projection device and a film stripping device. Of course, the film, projected in the liquid state, hardens by evaporation of a solvent when it is projected onto the wall. This projection takes place only after cleaning the tube.

According to a characteristic of the invention, the robot is provided with six drive wheels controlled independently carried by folding arms to adapt the size of the robot to the diameter of the duct, of an orientable turret on which the tools are fixed, of a evacuation pipe for lifting debris axially passing through the vehicle, the evacuation pipe being connected to the turret by a joint of electrical and pneumatic connections going to the turret via a rotary connector.

• la gestion des communications avec la station extérieure au tuyau ;
• l'asservissement des efforts mécaniques, de la vitesse de travail et de la luminosité ;
• l'avance dans le tube au moyen des roues motrices ;
• la rotation de la tourelle ;
• la régulation du pas de la brosse de nettoyage ;
• la régulation de l'éclairage ;
• la régulation de l'effort sur la brosse.

A micro controller on board the robot ensures:

• managing communications with the station outside the pipe;
• the enslavement of mechanical forces, working speed and brightness;
• feed into the tube by the drive wheels;
• the rotation of the turret;
• regulating the pitch of the cleaning brush;
• lighting regulation;
• regulation of the force on the brush.

The robot is permanently connected to the outdoor station which includes a computer and a video signal receiver which allows visual monitoring of the internal condition of the duct at any time and the correction of any faults in the control software. However, the "on-board intelligence" robot works normally by its internal program independently of the outdoor station, which usually only plays a controlling role.

The rotational movement of the turret allows the film to be torn off over the entire internal periphery of the duct by means of a single brush. This result is obtained by the combination of the rotational movement of the turret and the advance of the robot, the brush thus following a helical trajectory with constant pitch in the duct which ensures the removal and aspiration of a quantity regular polluted matter.

To perform its cleaning or coating function, the robot must be able to cross the elbows. To this end, the robot comprises a body from each end of which protrude three wheels spaced 120 ° apart, the wheels rolling inside the duct without sliding.

The robot is remote-controlled and its body carries all the connectors and the robot's electronic control card. On the body are fixed the six motorized arms with an anti-blocking device which will be described later. The body transmits the rotational movement for the operation of the brush and it is impermeable to dust brushed and sucked by the central pipe. The robot's microprocessor control system makes it possible to adjust the speed of rotation of the brush holder assembly, the support force of the brush on the wall, the support force of the arms on the wall and the speed of the drive wheels. The body of the machine or robot is in the shape of a diabolo, that is to say that its middle part is of smaller diameter than that of the ends. The motorization and the control of the wheels allow an offset of the body compared to the neutral line in the elbows. For crossing an elbow, we uses the differentiated pivoting of the arms which makes it possible to obtain an eccentricity at the offset of the axis of the robot relative to the neutral line of the conduit.

• La figure 1, une vue de face générale d'un robot permettant la mise en oeuvre du procédé ;
• la figure 2, une vue schématique en élévation du corps du robot ;
• la figure 3, une vue schématique d'un bras extensible ;
• la figure 4, un bras vu de côté ;
• la figure 5, une vue du bras porte brosse ;
• la figure 6, une vue de la liaison entre la brosse et la tourelle ;
• la figure 7, la vue arrière du robot équipé d'une brosse.

Other characteristics and advantages of the present invention will appear during the description which follows of a particular embodiment, given solely by way of nonlimiting example, with reference to the drawings which represent:

• Figure 1, a general front view of a robot for implementing the method;
• Figure 2, a schematic elevational view of the robot body;
• Figure 3, a schematic view of an extendable arm;
• Figure 4, an arm seen from the side;
• Figure 5, a view of the brush holder arm;
• Figure 6, a view of the connection between the brush and the turret;
• Figure 7, the rear view of the robot equipped with a brush.

In FIGS. 1 and 2, it can be seen that the robot comprises a body 1 has an axis of symmetry and a thinned central part, from which protrude according to the position of the robot six telescopic arms 2 of which only four appear on the figure. The body 1 has from the left to the right, a rear crown 3, a fixed part 4 and coaxially with the part 4, a rotating part 5 ending at the other end by a turret or tool holder 6 projecting from the front crown 7. The body further includes a turret motor 8, a transmission device 9, an electrical connector 10 and a pneumatic connector 11. The body proper is constituted by the two rear crowns 3 and front 7 stiffened by longitudinal partitions 12. In the center, the entire front part is in rotation to drive the turret 6. The rotational movement of the turret 6 is provided by the turret motor 8 and by two front and rear bearings (not referenced). The drive is provided by means of the gear 9. The pneumatic connector 11 is intended to allow the passage of compressed air from the fixed part 4 to the rotating part 5. This passage is effected by a connector three-way. The purpose of the electrical connector 10 is to pass the electrical current from the fixed part 4 to the turret 6. The rings are made of brass and the brushes are made of bronze-berylium, this connector is eight-way including two ways for the video signal and two for motor power.

In Figure 1, a coating projection device is mounted on the robot. This device comprises a projection nozzle B passing through the body of the robot by a conduit 30 which is, at its other end connected to a gun C which injects the liquid under pressure into the conduit. The nozzle B disperses the solvent-acrylic resin solution evenly inside the pipe. At its rear end, to the left of FIG. 1, a nozzle 30 on which the gun C is mounted allows connection to an evacuation duct, connected to the ground to a vacuum cleaner, making it possible to vacuum the particles detached from the wall during of the subsequent brushing operation. Of course, the microprocessor 29 is electrically connected to the central station by a conductive cable (not shown).

As shown in Figures 3 and 4, an arm 2 is pivotally mounted by one end on an axis 14 of the body 1 of the robot, its second end carrying a wheel or roller 13. Each arm is equipped with a motor 15, controlled by the microprocessor 29, intended to drive the wheel 13 on the wall. At the upper part of the arm there is a cylinder 16 armed with a spring 17 for calibrating the nominal bearing force of the roller 13 on the wall. The spring jack assembly makes it possible to obtain a greater or lesser inclination of the wheel relative to the body of the robot. The jack 16 is coupled with the spring 17 which helps or thwarts it. During operation, especially during the passage of an elbow, it happens that one or more wheels 13 are in contact under high pressure against a wall while the others are in a vacuum. The advance of the wheel therefore requires a greater current in the motor 15 thereof. This results in an increase in the intensity necessary for the progression of the wheel. According to a characteristic of the invention, this increase is detected by the microprocessor 29 of the robot which acts immediately on the jack 16 of the arm 2 to modify its inclination relative to the wall and reduce the intensity of the motor 15 to its nominal value. The motor 15 is connected to a gear train 18 which, with a given reduction ratio, drives the wheel 13. In the event of a power failure, the robot cannot fall thanks to the passive safety provided by the springs 17 motor arms. It is however necessary to provide a cable (not shown) allowing the removal of the robot in this situation. The main part of the arm is an aluminum plate 19 on which is mounted the main pivot 14 connecting the arm to the body 1 of the robot, the bearing housing and the engine spacer. The transmission is ensured between the motor and the roller by a belt, the rollers 13 are force-fitted in an aluminum housing and the inner rings are clamped between the shoulder of the shaft and the pulley. The spring 17 is a compression spring and it requires good guidance because it is subject to buckling. This guidance is provided by a guide having the shape of a piston.

Figures 5 to 7 show the mounting of the brush 20 on a brush holder arm 21 which is itself secured on the turret 6. In these figures we can see the camera 23 carried by the arm 21. The arm 21 is offset relative to the axis of the turret 6. The camera 23 is lit by electric bulbs (not shown), the flow of which is also controlled by the microprocessor 29 to avoid saturation of the target which would very often occur without this precaution.

At the end of the arm 21, pivotally mounted on the turret by an axis 32, is disposed a rotary circular brush 20 rotated by a motor 27 and a belt 28. The connecting piece or arm 24 allows the passage of the electrical wires the motor 27 and the passage of the compressed air conduits. The gear motor 27 and the actuator 25 which determines the inclination of the brush relative to the axis of the turret 6 are themselves dependent on the microprocessor 29. This inclination of the brush 20 determines the pressure of the latter on Wall.

The brush 20 is included in a casing 31 and is preferably removably mounted on a core, which allows the wear part to be interchangeable.

Claims (7)

A method of maintaining the walls of a pipe, characterized in that it consists in projecting a peelable film onto the walls, then after a certain period of use, mechanically disintegrating said film on which grease, detritus and soiling and vacuuming up the fragments. Method according to claim 1, characterized in that the application of the film and its disintegration are carried out by a remote-controlled robot comprising a programmed microprocessor acting on different organs of the robot, the microprocessor being connected to a station external to the pipeline to inspect said pipeline , the robot carrying lighting and detection means transmitting video signals to the external station. Cleaning robot for carrying out the method according to claim 1 comprising a hollow body from which projecting arms carrying wheels, characterized in that three arms are mounted on a diabolo-shaped body (1) (2) distributed at 120 °, each arm carrying a wheel driven independently of the others, one of the faces (7) of the body (1) carrying a turret (6) on which various tools can be mounted, lighting lamps and a video camera (23). Robot according to claim 3, characterized in that each arm (2) is articulated on the body (1) and comprises a motor (15) connected to the microprocessor (29), a jack (16), a spring (17), the motor shaft (15) being mechanically connected to the wheel (13) by a gear train (18). Robot according to one of claims 3 or 4, characterized in that the turret (6) is pivotally mounted under the action of a motor (8) by means of a pinion, rotary joints (10, 11) ensuring pneumatic transmission and transmission of control signals and video signals. Robot according to one of claims 3 to 5, characterized in that, on the turret (6) is mounted, on a pivot (24), a brush-carrying arm (21) carrying a geared motor (27) driving the brush ( 20) in rotation, and a tilt cylinder (25). Robot according to claim 4, characterized in that the microprocessor detects the intensity of the motor supply current (15) of an arm (2) and if this intensity reaches a certain threshold, the arm is inclined to limit the friction of the wheel on the wall.

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